SMALL SCALED REACTIVE MATERIALS COMBUSTION TEST FACILITY

BY

DAVID PAUL CHONOWSKI

THESIS

Submitted in partial fulfillment of the requirements

for the degree of Master of Science in Mechanical Engineering

in the Graduate College of the

University of Illinois at Urbana-Champaign, 2010

Urbana, Illinois

Adviser:

Professor Nick Glumac

ii

Abstract

Combustion of reactive materials forms an active area of research for reactive fragment and

structural materials applications. Currently, reactive fragment tests involve high velocity (1-2 km/s),

large caliber projectiles directed into blast chambers where overpressure is measured to quantify output.

Unfortunately, these existing facilities suffer many issues including high cost per test, which limits the

ability to perform true parametric studies, as well as limited access in some cases for diagnostics other

than transient pressure. To address these issues, we developed a small-scale reactive materials

combustion test facility based on the Remington .17 caliber rifle which safely launches projectiles at

velocities approaching 1.3 km/s. By making custom projectiles and firing these into a small chamber

with complete optical access, we are able to obtain transient pressure and capture high-speed imagery.

The setup also allows for optical measurements including pyrometry and spectroscopy. In this work the

diagnostic measurements are primarily the bullet velocity and chamber overpressure.

After completion of the design and installation of the laser optical chronograph and the

appropriate pressure transducers, several tests at velocities of 1.2 km/s were performed comparing inert

bullets with those comprised of reactive metals in air, 100% nitrogen, and 40% oxygen rich environments.

Therefore this paper outlines the major components of the combustion test facility, the system diagnostics

and the effect that different intermetallics in various environments have on combustion performance.

Results indicate that the facility performed as intended by capturing quantitative differences in the

chemical energy release of various energetic systems. Further, through the post-processing of specimen

residue with X-ray diffraction, the identification of reaction products provided better insight into the

chemical reactions contributing to the observed energy release assisting in the determination of elements

responsible for combustion performance.

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Acknowledgements

As an unfunded research project in the traditional sense, my thesis research would not have been

possible without the support of Prof. Nick Glumac. His continued mentorship along with Prof. Herman

Krier proved invaluable to the graduate learning experience by allowing me the time to troubleshoot

problems, create solutions, and implement under their guidance.

As members of our research group, Drew Coverdill, Bradley Horn, Lance Kingston, Jeff Mason,

Jennifer Peuker, and John Rudolphi each volunteered their time and expertise to me when asked. From

MATLAB code hints to assistance in conducting tests to opinions on design concepts, I extend my

gratitude to all of you. Further, Doug Logan, an undergraduate research assistant, devoted dozens of hours

during the bulk of my testing practically doubling my testing pace resulting in over 100 tests with the

small scale combustion facility.

Adam Hurst, senior research and development engineer at Kulite Semiconductor Products, Inc.

was very supportive in our research efforts by supplying a Kulite XTL-190-25SG pressure transducer.

The fast response time of this pressure transducer over the Gems 2200 series transducers allowed us to

capture the full and accurate pressure trace inside the pressure chamber.

David Costley, owner of Dave’s Firearms and Cycle Repair located in Urbana, Illinois, and Keith

Parrish, the research laboratory shop supervisor for the Mechanical Science and Engineering Department

at the University of Illinois both freely provided their knowledge of firearms and ballistics and aided in

the development of a safe and reliable bullet design.

Lastly, Dr. Richard Lee, Research & Technology Department, Naval Surface Warfare Center,

Indian Head Division, offered helpful advice during the early stages of this project on the design and

implementation of impact initiated reactive materials laboratories. His insight allowed me to gain a better

understanding into the design and operation of their facilities and apply that knowledge to my own

research.

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For my wife

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Table of Contents

Chapter 1 Introduction…………………………………………………………………………………...... 1

1.1 Energetic Materials Applications……………………………………………………………. 1

1.2 Types of Impact Initiated Test Facilities ……………………………………………………..2

Chapter 2 Objective of Current Research and Literature Review ………………………………………...3

2.1 Objective of Current Research ……………………………………………………………….3

2.2 Previous Work ………………………………………………………………………………..4

Chapter 3 Experimental Methods and Facility……………………………………………………………. 8

3.1 Overview……………………………………………………………………………………... 8

3.2 Determination of Energy Deposition from Pressure………………………………………... 10

3.3 Experimental Small Scaled Test Facility ……………………………………………………12

3.4 Projectile and Specimen Preparation……………………………………………………….. 24

Chapter 4 Results and Discussion………………………………………………………………………... 33

4.1 Projectile Velocity………………………………………………………………………….. 33

4.2 Blast Wave Analysis ………………………………………………………………………..34

4.3 Energy Release……………………………………………………………………………... 36

4.4 X-Ray Diffraction Analysis………………………………………………………………… 37

4.5 Pressure Chamber Environment……………………………………………………………. 37

4.6 Inert Baseline Tests………………………………………………………………………… 38

4.7 Copper(II) Oxide Systems in Air…………………………………………………………... 40

4.8 Tungsten-Zinc-Zirconium Systems in Air………………………………………………….. 43

4.9 Tungsten-Zinc-Hafnium Systems in Air…………………………………………………… 47

4.10 Potassium Perchlorate Systems in Air……………………………………………………… 50

4.11 Boron Carbide Systems……………………………………………………………………...55

4.12 Bismuth Oxide Systems in Air……………………………………………………………... 66

Chapter 5 Conclusions…………………………………………………………………………………… 68

5.1 Recommendations for Future Studies……………………………………………………… 68

5.2 Best Performing Systems…………………………………………………………………... 69

References………………………………………………………………………………………………… 71

Appendix A: Sample Preparation Equations……………………………………………………………... 73

Appendix B: Complete Test Results……………………………………………………………………… 75

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Appendix C: MATLAB Analysis Code…………………………………………………………………... 78

C.1: Quasi-Static Pressure Curve Analysis……………………………………………………… 78

C.2: Impulse Analysis……………………………………………………………………………. 80

C.3: Velocity Analysis…………………………………………………………………………… 82

Appendix D: Endevco 106/109 Settings………………………………………………………………….. 83

Appendix E: SOP for Model 700 Remington Rifle………………………………………………………. 84

Appendix F: Data Recording Sheet………………………………………………………………………. 85

Appendix G: Proposed Bullet Press Design Sketches……………………………………………………. 86

Appendix H: Remote Trigger Drawings………………………………………………………………….. 87

Appendix I: Mounting Block Sketch……………………………………………………………………... 89

Appendix J: Reactive Material Moisture Study…………………………………………………………... 90

Appendix K: Experimental Results in Energy Output per Volume………………………………………. 91

Appendix L: XRD Analysis Results……………………………………………………………………… 95

1

Chapter 1

Introduction

1.1 Energetic Materials Applications

“Reactive Materials (RM) denotes a class of materials that generally combines two or more

nonexplosive solids which, upon their ignition, react to release chemical energy in addition to the kinetic

energy when the high-speed projectile containing the reactive materials collides with the target” [1]. The

rare combination of stability under normal conditions and the ability to release large amounts of energy

make them attractive substitutes over more commonly used explosives such as TNT (trinitrotoluene) or

PETN (pentaerythritol tetranitrate). Moreover, the energy release and subsequently destructive capacity

can exceed standard explosives. For example, TNT generates 1120 cal/g [2] in blast energy while

materials such as aluminum and hafnium have been experimentally shown to exceed 2300 cal/g and 1400

cal/g respectively [3].

From the reduction of collateral damage to enhanced destructive capability of hardened targets to

increased effective range, energetic materials are an integral part of many modern defense systems.

Specifically, reactive materials significantly improve a systems ability to deliver damage to hard or soft

targets through: increased internal temperature form the chemical energy, enhanced blast and

overpressure, and deflagration of critical components [1].

According to the Committee on Advanced Energetic Materials and Manufacturing Technologies,

the United States is losing its capacity to create new energetic materials. In fact, “[t]he U.S. effort in the

synthesis of energetic materials at present involves approximately 24 chemists, several of whom are

approaching retirement. Few chemists are being trained to replace them” [1]. Clearly, the energetic

research community stands to benefit from increased academic involvement. Therefore, the

implementation of academic facilities such as the University of Illinois’ Department of Mechanical

Science and Engineering small scaled reactive test facility provides added opportunity to grow energetic

material research efforts fostering new ideas and potentially newly trained scientists in this field.

2

1.2 Types of Impact Initiated Test Facilities

Research surrounding reactive materials is a growing field due to the wide array of applications.

Typically these materials consist of intermetallics, metal-oxidizers, or metal-polymer combinations that

exhibit high strength, stability, and the ability to maintain multiple form factors.

Numerical simulation programs such as CHEETAH, a thermo-chemical coding language, are

excellent tools for determining the theoretical energy release of a reactive material specimen. In

comparison reactive material test facilities can experience variations (sometime significant) in terms of

the energy released by a given system. In the field of impact initiated energetic materials there currently

exist three main experimental methods [4]. The first being direct impact experiments consisting of a 25.4

mm bore powder gun that propels 19.4 g spherical reactive materials specimens initially mounted inside a

sabot towards a hardened metallic surface without any interference. Diagnostic equipment includes

photodiodes and spectrometers positioned to detect light emissions to determine product formation and

energy release. Another researched method is the indirect impact facility where a steel disk impacts a two

steel anvil configuration, which compress a grooved energetic pellet resting inside. Similar to the direct

impact experiment, high-speed imagery and spectroscopy provide the qualitative and quantitative sources

of data. Lastly, and most relevant to the research in this paper is the two-step impact experiment where a

thin .060 inch steel plate induces fragmentation in a projectile prior to impact on a hardened steel surface.

In addition to the previously mentioned diagnostic equipment, the two-step impact tests occur inside a

steel pressure vessel making the use of pressure transducers a relevant diagnostic [4].

3

Chapter 2

Objective of Current Research and

Literature Review

2.1 Objective of Current Research

The goal of impact-initiated energetic material research is to determine the reagent combination

that delivers maximum target damage. Therefore, the target and projectile interaction of a test facility

must closely resemble that of a real world scenario. Our small-scale facility and the larger ballistic

facilities at the Naval Surface Warfare Center (Figure 2.1), which our facility was modeled after, are

commonly referred to as vented calorimetric chambers for impact-initiated energetic materials. Chambers

with this design are initially sealed with a thin mild steel cover that allows for projectile penetration into

the chamber. The vent hole created from the initial penetration allows gases to escape as the reactive

metals combust inside the chamber after final impact on a hardened metallic surface. The exothermic

release of energy from the reactive materials results in a measurable increase of chamber pressure. More

specifically, the change in system pressure immediately following the chemical reaction, but before heat

transfer and losses is considered the quasi-static pressure. By quantifying the quasi-static pressure

generated from various constituents, experimentalists can draw conclusions about a material’s ability to

damage a target in real world applications.

Figure 2.1: Impact initiated “Octapig” (left) and “Bluepig” (right) test facility operated by NSWC [3]

Thus, the quasi-static pressure has become the most prominent metric of comparison for reactive

materials using this type of facility. Variations in the material type, mixture ratio, and particle size

4

contribute to distinct changes to energy release and in the quasi-static pressure allowing us to examine

parametric variations in reactive materials composition to isolate the key microstructural elements

responsible for optimized combustion performance.

2.2 Previous Work

Ames and Waggener

Richard Ames and Samuel Waggener published a paper, Reaction Efficiencies for Impact-

Initiated Energetic Materials, providing a performance comparison within a large-scale combustion test

facility of aluminum, tantalum, zirconium, and hafnium metals pressed with various fluorpolymers

binders. Each of the metal-binder specimens consisted of a 19.4 g spherical mass. Using a sabot the

projectiles were fired through a smooth bore powder gun (Figure 2.1) capable of achieving velocities of

2.4 km/s.

For the tests specifically referenced in the aforementioned paper, the metals were each propelled

at 1.2 km/s, 1.8 km/s, and 2.4 km/s. Comparison among specimens launched at similar velocities allows

for a relative comparison of the chemical potential of each specimen since the kinetic energy deposited in

the chamber is essentially equivalent. However, comparison of specimen performance launched at

different velocities requires the subtraction of the kinetic energy from the total measured energy release.

Ames and Waggener determined the chemical energy release (Total energy release=chemical energy +

kinetic energy) for each of the metals at each of the respective velocities. Figure 2.2 produced in their

paper depicts the chemical energy deposition of each metal-binder relative to the other specimens as well

as the theoretical energy release. As such, increased velocities yield performance closer to theoretical

results.

Figure 2.2: Comparison of velocity increases and theoretical energy release [3]

5

With the first experimental facility for impact initiated vented caloric calorimeter originating at

the Naval Surface Warfare Center, it is fitting that their work provides a basis of comparison. Figure 2.3

and Figure 2.4 below are two directly applicable charts as they depict materials of interest such as

aluminum, zirconium, tantalum, and hafnium.

Figure 2.3: Comparison of energy release at 1.2 km/s for various energetic metals [3]

Figure 2.4: Comparison of energy release at 1.8 km/s for various energetic metals [3]

6

Arguably the most interesting result from this paper was that materials with the highest

theoretical energy release did not always dominate in terms of combustion performance. As the

compression yield strength of a given material increases from weak, moderate, to strong (5.0 MPa, 12

MPa, and 15 MPa respectively), its performance deviates from the 100% theoretical values as seen in

Figure 2.5. Ames and Waggener suggested that “higher strength would likely result in better distribution

of the mechanical energy within the material and delay the development of hot-spot initiation points” [3].

They went on further to prove this statement by using chemically identical fluoroploymer binders which

each exhibit a distinct static compression yield strength. Since THV-500 has a yield strength of 12 MPa

while THV-220 has a yield strength of 5.0 MPa, the binders served as excellent materials for comparison.

Figure 2.6 displays how the weaker binder, THV-220, produces a more efficient reaction when compared

to the THV-500. This significance of this finding makes it an important point to consider when selecting

and comparing materials for testing in impact initiated systems.

Figure 2.5: Yield strength effects on energy release [3]

Figure 2.6: Relationship between efficiency and strength [3]

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Felts

Josh Felts conducted several velocity measurement tests using the same .17 caliber, Model 700

BDL, Remington rifle that is in use for the small scaled reactive materials combustion test facility (Figure

2.7). By thoroughly documenting the performance of various propellants and their respective quantities,

he demonstrated the velocity limitations of the rifle. Although the maximum charge for this rifle is

considered to be 24 grains with most powders, amounts exceeding 24 grains are obtainable, but require

close monitoring of the rifle and casings to avoid overpressure. Pressure from the gunpowder reaction

provides the force to accelerate the bullet through the rifle barrel. Theoretically a research assistant could

control the velocity from 0 to 1.4 km/s. However, in practice the range of charges is limited by the

minimum pressure required to eject the bullet without it becoming lodged in the barrel and the maximum

pressure that does not exceed the design limitation of the chamber. Through his efforts we were able to

avoid conducting our own series of tests to determine the best performing powder. With a ballistic

coefficient of .185 for the standard .17 caliber, 20 grain, Hornady V-MAX bullet, a muzzle velocity of 1.2

km/s (4,000 ft/s) creates 1.32 N of air resistance for a 1.30 gram bullet resulting in a difference of 1-2 m/s

when measuring the velocity one foot from the muzzle as Felts did with his facility or a three feet from

the muzzle in our facility. The nominal velocity difference made Felt’s results relevant in our facility.

Figure 2.7: Effect of gun powder amounts and brand on bullet velocity [5]

8

Chapter 3

Experimental Methods and Facility

3.1 Overview

The design of the pressure chamber is intended to simulate the conditions upon impact of a lightly

armored vehicle or aircraft in which a thin metal exterior shell encases larger and denser metallic

components. Under these circumstances the ballistic projectile fragments after piercing the outer shell and

continues to propagate through the medium until stopped by a denser surface. Similar to a water

calorimeter that equates the temperature change to the total amount of energy release, the impact chamber

allows for the measurement of pressure increases, which correlate to energy release depending on the air

conditions and volume of the chamber. Tests in confined spaces where the mass of the reactants was less

than 10% of the inside air demonstrated that an increase in air temperature was the strongest contributor

to the quasi-static pressure increase [6]. The energy transfer from a kinetic impact and the subsequent

chemical reaction of a reactive material create the damage to a target.

Figure 3.1: Projectile-Chamber fragmentation & interaction [6]

Each projectile’s total energy is the summation of its kinetic energy and stored chemical energy.

It is important to note that like many systems, not all of the energy is measureable. Following the initial

9

penetration of the fragmentation plate with minor losses in both mass and energy, the total energy

dissipates into various forms as depicted in Figure 3.2. Energy transfer through three major mediums or

sinks includes general losses, local blast pressures, and the global quasi-static pressure. General losses

include “heat that remains in the solid reaction products, heat losses to the chamber walls, and heat losses

that result from the venting process” [6]. But in application structural damage capacity is done by the

local and global pressures so the chamber pressure-time relationship or the global quasi-static pressure is

the most meaningful measurement when determining the total energy release from a given projectile.

Figure 3.2: Diagram of energy dissipation [6]

According to Ames, the quasi-static pressure is a more global phenomenon and a result of the

energy deposited into the chamber environment. Moreover, blast perturbations or local blast pressure

waves perform PdV work on the internal chamber environment further increasing the global quasi-static

pressure. Figure 3.3 demonstrates the measurable pressure that results from an energetic specimen impact.

Using a pressure transducer with an adequate response time, the high-pressure initial blast wave is

typically measured in the first few milliseconds. Following the initial blast is a series of undulations or

localized blast pressure waves traversing and reflecting, but dissipating inside the pressure chamber that

provide additional PdV work to the environment and lead to an increase in the global quasi-static

pressure.

In application a reactive material projectile would immediately affect a target upon penetration of

the target’s outer skin and subsequently be altered itself. Test facilities at the Naval Surface Warfare

Center typically use a 19.4 g homogenous sphere and experience an 8% loss in mass when perforating a

10

1/16th inch thick mild steel plate. Additionally, the projectile experiences a 20% reduction in velocity

when passing through the steel entry plate [6]. Although post-perforation velocity and mass

measurements were not conducted to determine the change in mass and velocity for this facility, it is

important to mention since the measured velocity is not the same velocity at impact due to the reduction

induced by the breaker plate.

Figure 3.3: Total pressure contributions to quasi-static pressure increase [6]

Since the standard .17 caliber Hornady bullet is primarily comprised of lead with a thin copper

coating which increases a bullet’s thermal capacity and resistance to deformation while traversing the rifle

barrel, there is a small, detectable level of chemical energy release when using an “inert” bullet.

Therefore, a baseline test is necessary for each chamber environment in order to differentiate between the

kinetic and chemical energy release from the bullet and the chemical energy release of the reactive metal

specimen. It’s important to note that rotational effect of the bullet created by the rifling of the Remington

700 Model BDL rifle is ignored to simplify the calculations as they are assumed to be insignificant in

energy disposition when compared to the translational kinetic energy.

3.2 Determination of Energy Deposition from Pressure

In order to calculate the total energy released by the reactive specimen and ballistic impact in the

chamber environment, we assume the pressure chamber acts as a closed system during the first few

milliseconds prior to reaching the maximum recordable overpressure. While also assuming an ideal gas

11

PV mair

RT

and a constant mass system, the quasi-static pressure created inside the chamber correlates to the energy

release through the following relationship:

(3.1)

The derivation of this equation is presented in Reaction Efficiencies for Impact Initiated

Energetic Materials [3]. By measuring the pressure increase and analytically approximating the quasi-

static pressure from the blast pressure data, the total energy release is determined. The specific heat ratio

(γ) for air varies with an increase in temperature. To complicate matters the temperature of the air inside

the pressure chamber varies significantly from 295 K at room temperature to 1500 K or greater depending

on the chemical energy of the specimen. Research at the Naval Surface Warfare Center found that inside

closed systems gas temperature increase is significant only within the first hundred milliseconds

following the projectile impact falling to a range of 500-1500 K during the venting process. To simplify

the calculations an assumption as to the ratio of specific heats is necessary. Researchers at the Naval

Surface Warfare Center-Dahlgren Division discovered that assuming a constant ratio of specific heats, γ,

of 1.4 is valid under most circumstances [6]. Therefore a specific heat ratio of 1.4 was an appropriate

value for the air inside the pressure chamber. With the volume, V, of the pressure chamber constant the

only variable in determining the energy release from each test is the peak quasi-static pressure, which is

measured from the recorded pressure traces.

It is also important to note that the energy release figures discussed in this paper are conservative

calculations as Equation 3.1 does not account for the mass of the projectile inside the pressure chamber.

With a volume of 5.56 liters the air inside the chamber has a mass of 6.67 g. In comparison to the average

bullet mass of 1.30 g, the projectile represents 19.5% of the internal mass of the system. This mass can act

as a sink, absorb energy in the form of heat, and reduce the energy contribution to the measurable quasi-

static pressure. Deriving the pressure-energy relationship with this consideration in mind takes the ideal

gas law in Equation 3.2 where P is the chamber pressure, V is the chamber volume, m is the mass of the

air, R is the universal gas constant, and T is the absolute temperature and substitutes Equation 3.3 where q

(also referred to as ΔE) is the energy released and Cv is the constant-volume specific heat results in

Equation 3.4.

(3.2)

(3.3) q mair

CvT

12

P

mair

R

V mair

Cv

mproj

Cproj

E

P

mair

1( )

V mair

mproj

Cproj

Cv air

E

(3.4)

Knowing that the universal gas constant, R, is equal to Cv(γ-1), Equation 3.4 is mathematically equivalent

to Equation 3.5. However, Equation 3.5 differs from Equation 3.1 in that the mass of the projectile now

influences the pressure-energy relationship. Using the constant-volume specific heat of air as .718

KJ/KgK and the specific heat of .13 KJ/KgK for a lead bullet (1.1 g of lead) doubled the estimated energy

output for a given system when compared to the methods in Equation 3.1 that assumed the mass of the

projectile has no effect on the measured pressure data.

(3.5)

This analysis shows that there are several ways to interpret the pressure data and by neglecting the mass

of the bullet, the energy results tabulated in Appendix B and derived from Equation 3.1 are very

conservative values for each system (50% reduced from Equation 3.5). Given the chaotic nature of the

fragmentation, it is difficult to discern how the energy is distributed post impact between the air or other

gaseous environments and the projectile mass since the projectile fragments with a range of particle sizes.

Further analysis of experimental results and residue form inert cases like those discussed in Chapter 4.6

could help discern the level of lead oxidation and influential fragmentation (in relation to Equation 3.5).

Additionally, the timescale at which the lead absorbs heat is significantly longer than that of air reducing

the effects of lead absorbing pressure enhancing energy. Therefore, for this work the results are based on

Equation 3.1.

3.3 Experimental Small Scaled Test Facility

Overview

Cost, system reliability and laboratory safety were all factors taken into consideration during the

design and construction of this small-scale facility. The system design is an integration of standardized

components that house a .17 caliber Model 700 BDL Remington rifle in a foam padded metal locker

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creating a noise reducing environment as seen in Figure 3.4. From the safety of an adjacent room, the rifle

trigger mechanism, which requires 4.25 lbf is remotely engaged through a sealed linear solenoid that

transmits 8.1 lbf. Figure 2.7 shows that a variation in gunpowder charge amounts (24 grain for 100%) and

brands, allows for the adjustment of bullet velocity with a maximum safe test velocity of 1.2-1.3 km/s.

Although the maximum velocity of the small scaled facility is less than those of the national

laboratories, the limitations of current weapon systems must also be taken into account. Velocities of

2.4km/s are attainable in large laboratory settings; however, they are less likely to be seen in fielded

weapon systems. For example, many of the current kinetic energy rounds such as those commonly

delivered in the M1A1/M1A2 Abrams Main Battle Tank operate at velocity ranges from 1.5-1.7 km/s [7].

In short, current deficiencies of a small scaled facility are not as significant when considering the

limitations of present day delivery systems. Research at the Naval Surface Warfare Center has also shown

that 1.2 km/s is fast enough to see reactive materials effects while velocities of 0.6 km/s are not [1].

Figure 3.4: Small scaled reactive materials combustion facility

Pressure Chamber

To properly measure the energy release, we required a facility durable enough to safely withstand

the initial impact and reflected shock waves created from a high-speed bullet, absorb and retain blast

pressures and fragments from the reactive constituents, provide optical access for diagnostics, and

accommodate multiple pressure transducers. The basic chamber design consists of a ½ in. thick, 8 in.

square section of A36 steel tubing spanning 10 inches in length. Two 4 in. x 8 in. sections were cut into

the steel tubing and covered with ½ inch thick polycarbonate plates functioning as ballistic windows and

secured by a 6061 aluminum frame. Serving as end caps are two 8 in. square, 1 in. thick A36 steel plates.

Elevating the chamber and acting as table mounting assembly are 4, 1 in. diameter 6061 aluminum rods

joined and supported on two 6 in. x 10 in. A36 steel plates.

The current chamber design allows for the placement of three pressure transducers in the ½

inch NPT fittings evenly distributed along the top chamber wall (Figure 3.5). The projectile first enters

the chamber by penetrating a 1/16 in. mild steel breaker plate, which induces fragmentation of the lead

bullet and the reactive constituents. Although certain materials may require the replacement of one sensor

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with a valve for immediate ventilation, utilizing all ports maximizes data collection. After several

preliminary tests in air, results indicated that typical experimental quasi-static pressures in air ranging

from 10-15 psig with maximum pressures reaching 25 psig.

Figure 3.5: Induced fragmentation & pressure transducer positions on pressure chamber

Figure 3.6: Gems pressure sensor mounted directly on top of the pressure chamber

Figure 3.7: Gems pressure sensor mounted on pressure chamber with a 1.50 in. tubing standoff

15

Due to the confined space of the chamber, the minor spatial difference of each transducer mount

did not attribute to any measurable variation in recordable pressure. Therefore, several peizoresistive

pressure transducers within the appropriate expected pressure range of 0 to 25 psig were selected. To

accurately record the peak blast pressure a XTL-190-25SG Kulite, 100 mv output, pressure transducer

was used in conjunction with the a Wheatstone strain gauge amplifier. The Kulite XTL series pressure

transducers are recommended for their high frequency response and resistance to vibrational noise. With

the blast peak pressure occurring in less than a millisecond, a voltage amplifier with a sufficient response

time equivalent to the Kulite XTL sensor was necessary. After testing several strain gauge amplifiers

with the Kulite pressure transducer, an Endevco 106, dual channel piezoresistive bridge signal

conditioner and an Endevco 109 power supply became the ideal choice.

Although not capable of recording the sub-millisecond peak impulse, the Gems 2200

peizoresistive pressure transducers enhance the reliability of the pressure measurements. A Gems 2200

series, 4-20 ma output, -15 to 45 psig and a -15 to 15 psig pressure transducer allowed for two additional

distinct pressure traces with each energetic specimen. Mounted in the middle is a Gems 2200 series, 4-20

ma output, -15 to 45 psig pressure transducer. Closest to the anvil is a Gems 2200 series, 4-20 ma output,

-15 to 15 psig pressure transducer. To mitigate unwanted vibrations the two Gems pressure transducers

were offset from the chamber by a 1.5 in. long and ¼ in. thick nylon tube (Figure 3.5). The use of nylon

tubing to offset certain vibrational “sensitive” transducers is necessary in order to capture usable data. A

simple test was performed with a Gems 2200 sensor mounted directly into the ½ in. NPT slot on top of

the pressure chamber without the use of any damping material. As expected Figure 3.6 depicts the

abundance of oscillations would make data post-processing challenging even with the best data filters.

Thus, the ¼ in. outer diameter and 1.50 in. long tube was a simple and reliable method to mitigate this

problem. Figure 3.7 shows the benefits in noise reduction with the nylon adapter.

Since the Gems sensors operate as a current output transducer, observable voltages are controlled

by adjustments to the terminal resistors fixed to the BNC output connector. A simple BNC style variable

terminator allowed for preferential adjustment in voltage output. Both 500 ohms and 1000 ohms were

suitable settings; however, all tests conducted and discussed in this paper were set to 1000 ohms mainly

due to the mathematical simplicity when converting the voltage output to pressure. Three pressure

transducers provide both experimental reliability and standoff distance variation (results showed that the

standoff distance between pressure transducers did not affect the pressure measurements).

Projectile Cabinet

Assembled by a senior design team, a standard athletic locker was modified into a projectile

housing facility, an incredibly useful container that creates a closed system during testing as well as

16

provides a secure manner to store the rifle when not in use. Moreover, the Remington 700 BDL rifle bolt

was stored and locked in a separate location as an additional safety precaution. The 12 in. x 18 in. x 72

in. Hallowell ValueMax locker lined with one inch egg shell insulation foam became the rifle housing

cabinet. To mount the rifle, a steel Caldwell Lead Sled DFT Rifle Shooting rest provided an excellent “off

the shelf” solution to securing the rifle and reducing the recoil especially when mounted one of the 30 in.

x 60 in. x 30 in. maple wood workbench tables via the U-hook and the ½ in. threaded rod [8].

The large door provided easy access to the rifle, rifle mount, and trigger solenoid. Minor

improvements such as a hinged rear access panel for rifle bore cleaning and two light duty cotton/nylon 3

foot long, 2 inch thick, hinged bar buckle straps created a cost effect method of increasing the rifle

stability within the Caldwell shooting rest and reducing test turnaround time. In the metal panel opposite

the mounted rifle Silver’s Machine, a local machine shop, cut a 3 in. diameter exit hole for the bullet.

Figure 3.8: Projectile cabinet with Caldwell shooting resting and Remington rifle

Figure 3.9: Rear access panel of projectile cabinet

Initially it was unclear as to the level of sound intensity that a muffled rifle would generate and

whether this facility could be used in the Mechanical Engineering Laboratory during normal business

hours. Several preliminary early morning tests demonstrated that although rifle blasts were noticeable to

17

KE1

2mv

2

someone in the immediate vicinity of the test facility, the noise did not permeate throughout the building.

As a result testing could be conducted inside the building and during normal business hours without being

a nuisance to others.

Laser-Optic Velocity Detection System

Along with the abrupt increase in chamber pressure, measuring the pre-impact velocity for impact

initiated reactive material experiments is critical to understanding their reactive tendencies. The kinetic

energy of each projectile is correlated to the pre-impact velocity by

(3.6)

where “m” represents the mass and “v” the velocity. Thus, doubling the velocity quadruples the kinetic

energy (KE). Therefore, even small changes in velocity can create noticeable variations in recorded

chamber pressure. Additional discussion on the effects of kinetic energy will follow in Chapter 4.1.

A high-speed chronograph was constructed using a series of optical lenses, a 645 nm, Class IIIa,

<5 mW, battery powered laser, two Thorlabs, DET 10A, hi-speed photodiodes, and a 3432 Picoscope

(digital oscilloscope). Initially velocity measurements were conducted without creating a diverging, 1-D,

laser sheet, instead relying on ensuring the highly accurate alignment of the rifle muzzle with the two

approximately 1.5mm diameter laser beams so that the 4.37 mm (.172 in.) diameter bullet would

successfully cross each beam resulting in measurable data. As a result, the chronograph facility in its

initial configuration failed to consistently capture the projectile’s velocity as it travelled between the

housing cabinet and the pressure chamber because the laser beam and bullet trajectory did not always

intersect. Incidentally the physical connection of the two supporting tables created a conduit for the

mechanical shock wave to travel from the rifle chamber to the chronograph system, possibly causing false

triggers as well. To improve the reliability of the system, multiple options were considered by designing a

series of lenses that would create and expand a 1-D sheet of light and collimate that sheet into the

appropriate height that would significantly reduce the possibility of a bullet failing to cross either the first

or second beam due to minor fluctuations in the bullet’s flight path. One option was to use the Kepler

lens arrangement where two positive lenses would effectively collimate the beam and one negative lens to

converge the light back to a focal point. A second option was to use the Galileo lens system where a

negative and a positive lens collimate the beam, which is subsequently converged to a focal point by

another negative lens. However, with either system the beam required an additional set of lenses for

collimation. Working with limited space and to reduce cost and complexity, the beam was not collimated

18

but lenses were placed accordingly to allow for the expanded beam to fully converge back on the

photodiodes seen in Figure 3.10 and 3.11.

Figure 3.10: Diagram of final proposed chronograph system

The 1.5mm laser beam was split by a 1 in. diameter 50/50 splitter lens that allowed 50% of the beam to

travel unimpaired to the hi-speed, Thorlab, DET 10A, photodiodes. This detector was chosen for its fast

rise time of 1 ns and appropriate wavelength range of 200-1100 nm. Using two plano-concave cylindrical

lenses (f=-40mm, H=10mm, L=12mm), the beam was expanded in such a manner that the 1-D sheet

height at the bullet path would be 14.5 mm (.57 in.). Clearly the 14.5 mm created a larger margin of error

than that of the original beam diameter of 1.5 mm. Two double convex, 50mm diameter, 50mm focal

length lenses refocused the diverging beam onto the photodiode receptor cells. Special attention must

always be given to the alignment of the laser beam onto each respective photodiode’s receptor cell. Non-

centered and incorrectly focused beams could result in failed measurements.

Figure 3.11: Completed laser/optic chronograph system

19

To properly record the bullet velocity several Picoscope setting variations were attempted prior to

determining the most suitable. Furthermore, due to a slight reduction in the beam intensity at the second

photodiode, Channel B, voltage sensitivity was set to a smaller range than Channel A. The Picoscope

software settings were as follows: Channel A: +/-500 mv, DC voltage and Channel B: +/-200 mv, DC

voltage, with 20 us/div and a sampling rate of 200 MS/s. The trigger was typically set at 30-40 mv below

Channel A’s mean voltage (200 mv & depending on battery power) and 10% from the initial recorded

data. During diagnostic tests of the velocity laser-optic chronograph, the recorded measurement signatures

did not accurately reflect the bullet passage as seen in Figure 3.12. More specifically a reliable velocity

graph would clearly depict a decrease in the mean voltage resulting from the bullet tip breaking the beam

and reducing the laser coverage of the photocell, a flat base where the bullet is blocking a 4.37 mm long

region of the 14.5 mm thick 1-D sheet, and then a quick rise returning to the voltage to its baseline.

Figure 3.14 displays the configuration of the two BNC cables connecting the hi-speed

photodiodes to the model 3424 Picoscope. Each BNC cable is terminated with a 560 ohm resistor

connected via a BNC grabber clips resulting in the reduction of RC response time.

Figure 3.12: Data from Laser-Optic Chronograph without BNC termination

Figure 3.13: Data from Laser-Optic Chronograph with 560 ohm BNC terminations

20

Figure 3.14: 560 ohm terminations on Laser-Optic Picoscope

Remote Trigger Mechanism

From a safety standpoint individuals using this facility require the ability to remotely trigger the

rifle from the safety of an adjacent room. Therefore, a sealed, push style linear actuator was integrated

with a hemispherical 3 in. x 1 in. rod designed to slide across the bottom of the trigger guard and guide

the rod directly into the front surface of the trigger. Since the Remington 700 BDL rifle requires 4.25 lbf

of trigger squeeze [5] to engage the firing pin, the 8.1 lbf generated by the solenoid is ample force to

successfully fire the rifle. Figure 3.16 depicts the design improvements over the work completed by the

senior design project [8]. The first improvement includes a support rod welded inside the 90 degree angle

bar supporting the solenoid. Prior to this modification when the solenoid engaged the trigger, a noticeable

amount of deflection in the angle bar occurred. Any deflection would reduce the force pressing on the

rifle trigger and potentially result in a misfire. Therefore, the simple design improvement resolved this

problem. Further Figure 3.15 depicts the original proposed “trigger guide rod” which consisted of a band

wrapped around trigger with a rubber grommet. The grommet would reside on an adjustable length screw

extending from the hemispherical rod. The intent was to provide a direct transfer of force from the

solenoid to the trigger. Instead the direct physical contact of the solenoid to the trigger was determined to

be a safety hazard. The final design shown in Figure 3.16 is the proposed design of Figure 3.15 without

the direct contact of the hemispherical rod to the trigger. Wire from the solenoid was adhered to the room

wall in 2310 MEL into 2312 MEL and connected to a power supply. Using a 24V, 7.2A push button

power supply to generate the current necessary to remotely trigger the solenoid as shown in Figure 3.16,

research assistants were now able to safely engage the rifle with adequate standoff distance and cover

from the thick concrete wall.

21

Figure 3.15: Proposed modifications to trigger mechanism

Figure 3.16: Remote trigger power supply (left) and final solenoid assembly (right)

Transition Section

A fire extinguisher cabinet serves as the transition section between the projectile cabinet and the

pressure chamber. Supported by 4 wooden legs (2 in. x 4 in. lumber) the simple, yet effective component

fulfills multiple purposes. First it satisfies an obvious safety requirement to close the entire facility. As

per the testing SOP (Appendix E), the transition section must be in place prior to loading a bullet in the

chamber. This precaution helps prevent obstructions in the bullet path. Secondly, the 1 in. eggshell foam

lining on the inside provides an extension to the projectile cabinet further reducing the blast noise and

containing ejected muzzle blast powder. Lastly, although the majority of the fragmentation travels into the

pressure chamber, small amounts of debris are emitted backwards, containment here is critical both for

safety reasons and to protect the sensitive laser-optic system.

22

Figure 3.17: Transition section (left) and the transition section with the laser-optic chronograph (right)

Fragmentation Plate

The projectile first enters the chamber by penetrating a 2 in. square by 1/16 in. thick mild steel

breaker plate, which induces fragmentation of the lead bullet and the reactive constituents. An entry plate

holder constructed from a 3.50 in. square A36 steel plate, secured with four 1/8 in. screws, and with a 1

in. diameter hollow center securely mounts the 2 in. square breaker plate. A crucial component to testing

is selecting the appropriate plate thickness since too thick of a plate will force a premature reaction while

too thin of a plate won’t effectively disperse the bullet and its inner constituents. Experimenters at the

Naval Surface Warfare Center found that a 1/16 inch mild steel was ideal. Therefore, we set out to

confirm that this is the case in our scaled combustion facility. It is also important to note that their most

commonly used projectile was a 0.65-1.0 in. diameter sphere whereas ours is a standard .17 caliber bullet

[9]. The images in Figure 3.19 are results obtained from a Phantom v5 high-speed digital imagining

camera varying the thickness of the metal skin. The top image shows the bullet filled with 100 mg of two-

micron aluminum travelling at 1 km/s inside the pressure chamber without the use of the fragmentation

skin. The middle image shows the effects of a reactive aluminum filled bullet with the equivalent mass

and traveling at an equivalent velocity passing through a 1/16 in. metal plate. The bottom picture shows

the effects under the same conditions of a 1/8 in. metal plate. In this instance there was significantly more

reactivity both at the metal plate as well as in the airborne fragmentation. Since the goal was to initiate

fragmentation, not the chemical reaction, and concentrate a majority of the projectiles mass onto the

hardened anvil, a 1/16 in. plate was chosen as the most ideal for this application. Additionally, the thicker

the entry plate the more likely a reaction will occur outside of the chamber, and subsequently outside the

measurement reach of the pressure transducers.

23

Figure 3.18: Fragmentation plate holder (left) and mounted 2 in. diameter shaft collar with anvil (right)

Figure: 3.19: Bullet travelling at 1 km/s with no metal plate (top), a 1/16 in. metal plate (middle), and a 1/8 in. metal

plate (bottom)

Impact Surface

The type of metal, more specifically the hardness of that metal, plays a significant role in amount

of energy that performs mechanical work on a projectile and specimen as opposed to portions of the

kinetic energy transferring to anvil deformation. Similar impact energy tests at the Naval Surface Warfare

Center found 38-40 HRC for a 4340 steel anvil adequate [4]. By increasing the hardness of the metal, the

kinetic energy lost to the deformation of the metal is reduced. With the goal of selecting a cost effective,

hard metal, the final design consisted of a 2 in. diameter, 1 in. long metal disk of heat treated, air cooled

4140 steel with approximate hardness values of 50 HRC as tested on the Rockwell Hardness Tester.

Figure 3.20 shows the anvil surface before and after a test with approximately 100 mg of

aluminum travelling at 1 km/s. Anvils are stored after each test for potential future fragmentation

analysis.

24

Figure 3.20: 4140 Steel anvil surface before (left) and after (right) an impact-initiated chemical reaction

3.4 Projectile and Specimen Preparation

Custom Bullet Design

To successfully conduct impact-initiated tests of energetic materials, a transport mechanism is

necessary that can achieve velocities of 1.2 km/s or more, shelter a significant portion of the energetic

material specimen from reacting prior to impact on the anvil, and provide a stable flight path allowing for

velocity measurement and a repeatable direct surface impact. The first transport mechanism attempt in

Figure 3.21 was a .605 in. long, .171 in. diameter copper cylinder with a hollowed inner cavity. Despite

the advantage of increased capacity over using a standard .172 caliber bullet, the cylindrical design had

several inherent challenges with seating correctly in the rifle chamber and potential stability problems

travelling through the bore.

Figure 3.21: Standard Hornady, .17 caliber bullet (left) & proposed custom bullet design (right)

Figure 3.22: Final (left) & initial proposed (right) custom bullet design

25

Figure 3.23 and Figure 3.24 display a series of stress analysis tests conducted with the stress

analysis environment in Autodesk Inventor. Approximating chamber pressures of 50,000 psi at the rear of

the proposed bullet cylinder [10], Von Mises stress analysis captured likely points of failure for a bullet

machined from .171 in. diameter round stock copper. Computations showed that internal cylinder failure

was plausible potentially resulting in structural degradation while travelling inside the rifle bore and

unwanted fragmentation at the muzzle exit. Other material choices were feasible and could have provided

more structural integrity. However, after completion of a prototype (Figure 3.22) other complications

became apparent. Since typical chamber pressures for the Remington Model 700 rifles approach 50,000

psi, any obstructions preventing the escape of high velocity gas could significantly damage the rifle.

Furthermore, without the conical tip, the entire length of the cylindrical bullet would remain in contact

with the rifling and inner surface of the rifle bore. One possible outcome would be a reduction in bullet

velocity due to increased friction while another is the potential collapse of the thin bullet walls from

prolonged contact resulting in a failed test. Despite minor losses in mass transport capacity, the second

design eliminated any rifle integration or safety concerns. Standard 20 grain, .17 caliber, Hornady bullets

were machined creating a cavity capable of holding 100-300 mg. Preliminary results demonstrated that

this amount is adequate for reactive material comparison.

Figure 3.23: Von Mises Stress from 50,000 psi on proposed bullet design

Figure 3.24: Von Mises Stress from 50,000 psi on .17 caliber Hornady bullet

26

Measuring the Constituents

For each energetic material system the proportion of fuel to oxidizer or secondary energetic

constituent in the case of boron carbide systems was determined from a plausible set of products as

predicting all possible products without a more robust software package was outside the scope of this

research project. A representative example would be the Ti-B4C system where the sample mixture ratios

were created from the following stoichiometric equation:

3Ti (s) + B4C (s) → 2TiB2 (s) + TiC (s) + 680 KJ (3.7)

A Ti-B4C system reacting in argon could yield a series of condensed products (Ti, B, C, B4C, TiB, TiB2,

TiC) as well as a host of gaseous products (Ti, Ti2, B, B2, C, C2, C3, C4, C5, BC, B2C, BC2) [11]. Clearly

to balance each equation based on all known or suspected products would have been a cumbersome feat

without the use of a more advanced software packages. Given that the vast majority of tests were

conducted in air at normal room conditions (14.7 psia & 71 oF), the predominant concentration of oxygen

and nitrogen in air added another set of possible reactants to each system. A “best guess” equation of

likely products based on favorable heat of formation values was used when mixing each system. In

addition most all systems were stoichiometrically balanced with some exceptions where a fuel rich or fuel

lean mixture tested performance variations. Appendix A is a reference for the equations used to mix the

list of systems found in Appendix B.

Moisture Content

While testing an array of energetic systems certain specimens of the same composition exhibited

variations of 10-20% in performance as measured by the recorded chamber pressure. Although numerous

factors such as impact velocity, exact impact location on the breaker plate and anvil, moisture content in

the ambient air and the test specimen, and particle fragmentation patterns contribute to the measured

performance of a each sample; it seemed reasonable to a large extent that the moisture levels of mixed

powders were measurable and controllable. Moreover, the significant fluctuations in the outside air

temperature and relative humidity from May through August when the ballistic tests were conducted

made it worthwhile to investigate. Using the W-Zn-Zr system mixed in the weight ratio of

17.5%/16.0%/66.5% respectively, a series of tests varying the moisture content from 0% to 15% were

conducted to determine whether moisture levels affect the energetic performance and, if so, to what

extent.

27

By inducing steam at 100 oC and ambient pressure into vacuum dried samples of W-Zn-Zr,

various moisture content levels were achieved and tabulated in Appendix J in terms of gravimetric water

content expressed in terms of the water mass divided by the total sample mass. Referring to Figure 3.25 a

clear pattern emerged that, for the most part, specimens with moisture contents greater than 7% show

degraded performance while percentages less than 7% did not appear to significantly alter the outcome.

Further the fluctuations of the 3.5% moisture content sample suggested that although moisture can alter

performance, other factors are more likely causing the variations in recorded pressure values. Appendix J

references a series of observations performed to determine how much moisture is absorbed in a sample

removed from 24 hours of storage in a vacuum (-14.7 psig) that is placed in ambient air for 15 days.

Results indicated that the moisture content increased, but by less than 1%. This nominal change could

also be partly a result of deviations in the scale measurements making the moisture content almost

negligible. Thus, it is unlikely that any significant moisture intrusion during sample preparation resulted

in the observed performance anomalies. As such, other aspects of the sample preparation process

discussed below were investigated.

Figure: 3.25: W-Zn-Zr performance depending on moisture content

28

Mixing the Constituents

Equally as important to conducting a repeatable experiment with the diagnostic equipment

functioning properly is creating homogenous mixtures of the fuel and oxidizer or multiple intermetallic

combinations. After weighing the correct proportions (rich, lean, or stoichiometic) from the balanced

reaction equation, a few ounces of hexane, mixture of isomers, ACS reagent >98.5% were used in

conjunction with an ultrasonic processor at an amplitude setting of 80 and run for a period of four

minutes to thoroughly mix each sample. For most specimens the hexane solution created using the

ultrasonic processor was adequate for producing homogenous mixtures. Hexane polymers are typically

nonreactive and evaporate readily under normal conditions and at an increased rate inside a vacuum. To

quickly and sufficiently remove the hexane from each sample, a 4 CFM, 1/3 HP, high performance

vacuum pump was used to create a vacuum at -100 kPa inside a Fisher Isotemp Vacuum oven. For this

application, it was unnecessary to heat the samples as the hexane evaporated at room temperature.

General practice was to prepare the samples one day, store the prepared mixtures inside the vacuum

overnight, and remove and press the powders the following day. Hexane served, in most cases, as an

adequate medium for creating homogenous mixtures. Unfortunately, systems such as W-Zn-Zr failed to

mix uniformly in part, due to large differences in material densities and settling rates leaving layers of

elements or “swirls” opposed to well-mixed samples after use in the ultrasonic processor. To resolve the

settling issues, insoluble samples unable to thoroughly mix in Hexane were mechanically hand mixed

with two, 6 mm steel balls in translucent polyethylene bottles for two minutes.

After weighing and properly mixing the reactive powders, each test sample required a facility

capable of securing the bullet while pressing the powders inside the inner cavity. Figure 3.26 is a

conceptual diagram of a proposed system where a research assistant would start by placing a series of .17

caliber bullets into a mounting block and securing it with a back plate. The assembled mounting block

would then fit to a movable base resting on the press. Similar to how an adjustable stop works on a

common table or floor drill press, a threaded rod allows the operator to raise and lower the dial

controlling the pressing force. Although not pictured, a tension scale attached in a similar manner could

accommodate the same purpose. Thus, the table sized, hand powered, miniature press could provide a

simple and effective means to construct reactive bullets for testing. Ironically since this design was

modeled after a standard drill press, the simplest solution to this phase in the sample preparation phase

was to acquire a drill press and create the necessary modifications to suit our needs. Therefore, a

personally owned Craftsman, 2/3 HP, 10 in. drill press with an adjustable base plate was an almost

complete solution as seen in Figure 3.30. Figures 3.27 through 3.30 show the sample preparation process.

29

Figure 3.26: Proposed bullet press design

Figure 3.27: Ultrasonic processor (left) and Fisher Isotemp vacuum oven (right)

30

Figure 3.28: Securing bullet inside press mount

Figure 3.29: Placing specimen powder inside bullet cavity

Figure 3.30: Pressing powder inside bullet cavity using drill press mount

31

Loading Ammunition

Following the safety requirements and standard loading procedures for rifle ammunition [12],

each casing was visually inspected for anomalies that could affect safe firing inside the rifle chamber.

Next, firmly twisting the deburring tool over the outer and inner neck of the casings removed minor

metallic burs which could inhibit the bullet insertion during loading or the casing position inside the rifle

chamber. CCI small rifle primers were then pressed into each casing using a RCBS single stage press

mounted to the testing table. Measuring 1.62 g (25 grains) of BL(C)2 Hodgon powder for each casing

provided enough propellant to achieve a muzzle velocity of 1.2 km/s (4,000 ft/s). It is important to note

that all tests exceeded the maximum BL(C)2 Hodgon powder label recommendation of 24 grains by 4%,

but that realistically, with proper precautions, the rifle chamber can handle loads that slightly exceed 24

grains. Best practices include monitoring the condition of the expended casing looking for excessive

expansion while also inspecting the primer, as flat primers are another indicator of overpressure. Firing a

few tests with a “low-end” charge of 20 grains, for example, will provide an excellent baseline for the

expended casings to use in comparison with those of greater charges to monitor for early overpressure

warnings before they cause serious damage to the rifle. Selecting the appropriate type of gunpowder and

quantity can alter the muzzle velocity of each test. Therefore, consistency is essential to both material

selection and amounts in order to achieve repeatable velocities. Although most gun powder

manufacturers annotate grain to velocity metrics on their labels, these values are often measured at a

distance of 15 feet from the muzzle and back-calculated to determine the velocity at the muzzle exit.

Generally a light coat of lubricant placed with the forefinger and thumb around the neck of the cartridges

prevents jamming inside the bullet press. The reactive material bullet was applied at the tip with clear

finger nail polish as a sealant. The final step in the cartridge preparation was the loading of the compacted

and sealed .172 caliber reactive material bullet with a rifle cartridge filled with 25 grains of rifle powder

in the RCBS press.

Effects of Atmospheric Conditions Ballistics

Complete control of the bullet speed is practically impossible. Once 25 grains of Hodgon BL-

C(2) rifle powder proved adequate in achieving 1.2 km/s, the focus was on a consistent reloading process.

Just as environmental conditions affect energetic materials, so does the environment affect the gunpowder

performance. For each powder type and atmospheric moisture content a level of moisture exists referred

to the moisture equilibrium. This moisture equilibrium will remain constant given that the moisture

content in the surrounding air remains unchanged. Typical moisture equilibriums can vary from .20

percent moisture content when the ambient air is at 10 percent humidity to 1.5 percent when the ambient

air is at 90 percent humidity [10]. Along with relative humidity, temperature changes can alter ballistic

32

Velocity T( ) V70

1 .000405 T 70( )[ ]

performance by changing the gravimetric density of the gunpowder. Generally speaking, although the

relationship may not always be linear, increases in temperature reduce the gravimetric density, but

increase the pressure and the bullet velocity. Heating gunpowder to high storage temperatures (> 140 oF)

can drive out some residual moisture; however, this procedure can also alter the burning performance of

the powder by burning off certain volatile solvents such as acetone and removing deterrent coatings from

the powder surface [10].

Mathematically the velocity in feet per second (fps) is a function of the bullet velocity at 70 oF

and the current ambient temperature (T) in degrees Fahrenheit:

(3.8)

This relationship from [10] shows that a fluctuation in 5 oF above or below would change the

bullet velocity 10 ft/s. Although this change is minor, coupled with other potential inconsistencies such as

whether the rifle powder is predominately in the front of the casing, towards the primer in the rear, or

evenly distributed could also affect the rate and level of pressure reached inside the rifle chamber.

Consistency in the type of primer and powder, the handling and storage of raw materials or prepared

bullets, the avoidance of moist environments, and the utilization of all equipment as intended such as

keeping the rifle powder in the appropriate container will help ensure that each test is within the desired

velocity parameters.

33

Chapter 4

Results and Discussion

4.1 Projectile Velocity

The amount of gunpowder in each casing strongly correlates to the muzzle velocity of the bullet

as it exits the rifle and enters the pressure chamber. After several tests using a variation of 22, 24, and 25

grain charges, 25 grains (1.6200 g) became the ideal charge that consistently and safely achieved

velocities close to 4,000 ft/s. Figure 4.1 below depicts a distribution of 74 tests conducted in air each

with exactly 25 grains of Hodgon BL-C(2) rifle powder. With a mean velocity of 3,973 ft/s and a standard

deviation of 69 ft/s, 68% of the tests resided within this range. Unfortunately, the amount of grain charge

is not the only factor affecting the bullet muzzle velocity.

Figure 4.1: Variation in bullet velocity with a 25 grain charge

3,750

3,800

3,850

3,900

3,950

4,000

4,050

4,100

4,150

0 20 40 60 80

Vel

oci

ty (

ft/s

)

Test Numbers

Velocity Data Point

Upper Limit (1 Standard Deviation)

Lower Limit (1 Standard Deviaiton)

34

A t( ) Ao

e

t

4.2 Blast Wave Analysis

Pressure and velocity are the two primary and critical diagnostic components for this research and

for determining the kinetic and chemical energy release of each reactive material system. With each

different specimen exhibiting its own unique pressure trace, impulse is one metric for relative

performance comparison. Research into blast wave performance discovered that the numeric value of the

impulse is “an important aspect of damage-causing ability” [2]. Explosive Shocks in Air dissected a blast

wave impulse into three main components: the peak, the time span for the first positive phase, and the

decay behavior. Energetic systems containing larger amounts of material are more likely to exhibit both

positive and negative phases on a pressure-time plot. In the case of our scaled facility, dealing with

relatively small amounts of energetic material constrained the pressure curves to a single positive phase

without any noticeable negative phases for an air or nitrogen based environment tests. Trace negative

phases were observed in the 40% oxygen environment.

Although the positive phase of the pressure wave impulse correlates strongly with a system’s

ability to damage a target, impulse as a unit of force-time does not translate directly into energy based

units. Figure 4.2 below shows the correlation between impulse (PSI-ms) measured and total energy

(Joules) calculated using the method outlined in Chapter 3.2 with a ratio of specific heats of 1.40 for and

pressure chamber volume of .0056 m3

Using MATLAB the decay portion of each pressure curve was fit to a logarithmic decay function

of the form:

(4.1)

where AO denotes is the peak quasi-static pressure or overpressure, e the base of natural logarithms, t the

instantaneous time, and τ the exponential time constant. The logarithmic decay function is intended to

model curves only in the positive phase and not in the negative phase when pressure drops below 0 psig.

Nevertheless, this is not a concern since the quantifiable destructive section of the blast occurs in the first

positive phase and nominal secondary negative phases were only observed in the 40% oxygen tests.

Fitting equation 4.1 to the decay section of the pressure curve 30-50 ms to after the initial blast until the

pressure returns to zero provided enough data to accurately depict the decay free from any distortions

typically recorded post-impact from shock wave perturbations and mechanical vibrations inside the

pressure chamber as seen in Figure 4.3 in blue. Further, the abrupt rise in over-pressure from the initial

shock wave was modeled as a linear curve in blue as well. The linear equation and logarithmic equation

derived from the curve fitting were used to calculate an extension, and the intersection of the two curves

yielded the maximum quasi-static overpressure of each pressure trace. This computational process was

35

repeated in MATLAB for each pressure transducer associated with the 110 energetic material systems

examined in this research.

Figure 4.2: Linear fit of total energy and impulse for 91 tests conducted in air with an R2 of .91

Figure 4.3: Sample calculation of curve fitting and intersect to determine the maximum over-pressure

36

4.3 Energy Release

As discussed in Chapter 3.3 the total energy dissipation is the summation of the kinetic and

chemical energy release of each specimen. After determining the peak quasi-static pressure from the

measured pressure data and the kinetic energy from the velocity data, the chemical energy is derived

simply as:

Total Energy = Kinetic Energy + Chemical Energy (4.2)

Figure 4.4 is a fictitious energy bar, yet it is representative of the total energy breakdown of energetic

materials used in this facility as for several of the tests in air. Approximately 25% of the energy released

is a direct result of the kinetic energy (and oxidation from relatively inert elements discussed in Chapter

4.4), while the remaining 75% is generated from the stored chemical potential of the reactive material.

Therefore, the chemical energy component is the metric of comparison as it provides a performance

gauge between different reactive materials and against the theoretical performance helping us to

understand what variations and elements enhance combustion performance. A complete tabulation of the

total, kinetic, and chemical energy release for each system can be found in Appendix B.

Figure 4.4: Hypothetical example of total energy breakdown

37

4.4 X-ray Diffraction Analysis

X-ray diffraction (XRD) was chosen as a quick, non-destructive method for analyzing several of

the residue samples from reactive materials of interest. Information on a peak intensity, width, location,

and phase position all provide indicators as to the polycrystalline structure [13] and ultimately the

material itself through the use of robust analytical software packages. Clearly, with over 100 possible

residue samples available for analysis, time became the limiting factor in the residue processing. The

Siemens D5000 XRD Diffraktometer recorded the phase angle and intensity for the systems of interest

and the MDI Jade software compared the results to over 200,000 possible chemical compounds using the

various powdered diffraction files (PDF) libraries. The challenges with this method are that non-

crystalline or amorphous structures, which lack a uniform lattice structure, are more difficult to identify

and would not be clearly apparent, except by a non-distinct “hump” in the collected data. An additional

challenge to the analysis, which would be the same for any post-processing technique, was that only small

amounts of residue were available. Starting with only 100-300 mg, the residue collected comprised

mainly of lead, smaller amounts of copper, metallic shrapnel from the anvil and inner walls of the

pressure chamber and lesser amounts of the critical reaction products. With the use of #40, #200, and

#325 sieve each residue sample was filtered down to the <44 μ level, thus removing a large proportion of

the unwanted debris from each sample. Further, a single crystal quartz, zero background holder, with a

.25 in. diameter inner cavity aided in the reduction of background noise, which was imperative when

looking for critical reaction products that in some cases only existed in trace amounts compared to the

overall sample.

From each reactive material system, one of the better performing sub-systems was chosen as a

candidate for XRD in hopes that an increased energy release would possibly enhance the production of

other less prevalent reactions and yield noticeable signatures. Processed residue samples not mentioned in

the discussion below can be found in Appendix L.

4.5 Pressure Chamber Environment

In most cases the energy released by the reactive metals originated from some level of oxidation

with the reactive specimens. Therefore, to better understand the oxidation effects different levels of

oxygen rich environments were tested using inert bullets. A 21%, 40%, 50%, 75%, and 100% by volume

oxygen rich environments were compared among each other and to a 100% rich nitrogen environment.

It’s also important to note that despite using the terminology and referring to the bullet as “inert,” the lead

and copper content do oxidize. This topic will be discussed in Chapter 4.6.

38

Variations in the volumetric proportion of oxygen inside the pressure chamber alter the level of

oxidation of energetic specimens and ultimately the energy released and the post-impact pressure

measured. To create a 50% oxygen environment and starting with ambient conditions the pressure in the

chamber was reduced to 9.91 psia and filled with pure oxygen to 15.7 psia resulting in a 50% oxygen and

50% inert (nitrogen) environment. For a 75% oxygen environment the pressure was reduced to 4.88 psia

and subsequently filled with pure oxygen to 15.7 psia resulting in a 75% oxygen and 25% inert (nitrogen)

environment. As the pressure chamber is not one solid piece, but an assembly of various components such

as the window panes, metal end plates, and a fragmentation plate mount thereby restricting the pressure

chamber’s ability to achieve a perfect vacuum seal, it’s limited to 1 psia using a ¼ HP Vacuum pump. To

achieve a near perfect oxygen environment the pressure chamber required three evacuation and fills. By

first evacuating to 27.9 in. Hg refilling to slightly above 14.7 psia for three cycles with the final cycle

being pressurized to 15.7 psia to reduce the mixing effects from outside air following penetration, a

99.9% pure oxygen environment was achieved.

4.6 Inert Baseline Tests

Averaging the total energy results from five inert tests conducted in air with the standard .17

caliber Hornady bullet resulted in a total energy output of 386 J. This value was initially thought to solely

represent the kinetic energy transferred into measurable shock waves and pressure perturbations inside the

chamber. The terminology of “inert” or baseline test is somewhat deceiving as a copper coated, lead

bullet with a conical polymer tip undergoes a chemical reaction which became increasingly apparent in

oxygen rich environments as seen in Figure 4.5. Contributing chemical energy components were the

formation of PbO and possible trace amounts of PbO2 and FeN resulting in the measurable amount energy

release. Since each residue sample is predominately lead, this left only 8-20% of the mass for the

energetic materials depending on the sample density. Therefore, conclusive XRD results for certain

compounds are unlikely as phase angles are often shared with either Pb, PbO, or Cu, which are in

abundance (Figure 4.6). Excluding the mass associated with polymer tip and the copper jacket the

standard .17 caliber Hornady bullet contains approximately 1.10 g of Pb. Considering Equation 4.3 a

bullet would yield 1154 J of energy if 100% of the lead combusted. Figure 4.5 shows that 13% of the

bullet reacts in air while 45% of the bullet reacts in a 100% oxygen rich environment resulting in the

formation of PbO.

2Pb (s) + O2 (g) → 2PbO (s) ΔH= -217.3 KJ/mol (4.3)

39

Figure 4.5: Standard .17 caliber Hornady bullet tested in various environments

Figure 4.6: Standard .17 caliber Hornady bullet tested in a 40% oxygen environment (Test #105)

40

Fuel

Oxidizer

Mixture

Fuel

Oxidizer

Stoich

4.7 Copper(II) Oxide Systems in Air

Tests outlined in Chapter 4 and Chapter 5 were conducted on a constant volume basis where each

bullet cavity (.035 cc) was completely filled with reactive material, pressed, and sealed. Appendix K takes

into account the units of energy output per volume (J/cc) for all discussed systems. However, for

simplicity many of the charts in this paper will only refer to joules as the energy output.

A -325 mesh, <44 μ, copper(II) oxide powder served as an oxidizer for various fuels and was

mixed with 2-3µ zirconium, <44 µ tungsten, <44 µ titanium, <2 µ tantalum, <44µ hafnium, 3 µ

aluminum, and 80 nm aluminum powder. The first objective was to understand how a rich versus lean

mixture can affect the results for a well-known oxidizing metal. Aluminum-copper(II) oxide was selected

as the system to study and mix in rich, lean, and stoichiometric proportions to understand how

stoichiometry affects combustion performance.

Stoichiometric reaction for aluminum:

2Al (s) + 3CuO (s) → Al2O3 (s) + 3Cu (s) + 1204 KJ (4.4)

To gauge the performance effects of changes in the fuel, rich and lean Al-CuO ratios were

calculated using the stoichiometric equation as a baseline. Samples labeled “rich” were mixed using an

equivalence ratio, ϕ, of 2 while the “lean” samples were based on a ϕ of 0.5.

(4.5)

As anticipated the rich Al-CuO mixture outperformed all other Al-CuO systems, and the

stoichiometrically balanced mixture outperformed the lean mixture. To put the energy enhancement in

perspective, by quadrupling the amount of aluminum (by mass) in the rich mixture increases the chemical

energy output by a factor of 2.5 over that of the lean mixture. Additionally and although not conclusive as

the nanoscale results are of a single test, a strochiometric mixture of 80 nm aluminum powder did not

contribute to an improvement in the combustion performance of the Al-CuO system over the 3 µ

aluminum powder. In the absence of a nanoscale copper(II) oxide, a 44 µ powder acted as an oxidizer, but

most likely served as the limiting factor to improved performance. Recommendations for future tests

41

would be to conduct a series of nanoscale tests using both nano size powder for the fuel and the oxidizer.

Another peculiar result for the Al-CuO oxide system as per Figure L.3 in Appendix L is that the Al2O3

was not distinctly visible in the XRD analysis because the Al2O3 peaks shared phase peaks with other

materials such as copper.

Figure 4.7 and Figure 4.8 show the graphical relationship for the Al-CuO systems as well as other

metallic fuels. Titanium is one of the best performers in the copper(II) oxide series. Titanium and

copper(II) oxide were prepared under the assumption that the process yielded titanium(IV) oxide and

copper in an exothermic reaction. The XRD results indicated minor traces of titanium(IV) oxide and the

disproportionally large release of energy suggests that oxidation of titanium was likely. Also of interest is

the relatively high reaction level of the zirconium, hafnium, and aluminum in each of their respective

systems. In comparison to the maximum theoretical value, zirconium exhibited 77% reaction completion,

74% for hafnium, and 58% for aluminum. These are very optimistic results and demonstrate that

velocities of 1.2 km/s are sufficient for achieving significant levels of reactive material combustion in our

facility. In comparison, to the 13% of lead combustion in air as discussed in Chapter 4.6, it is reasonable

to argue that the compressed reactive material powders react more readily than the solidified lead bullet.

Figure 4.7: Energy release from various CuO combinations

42

Figure 4.8: Energy release per gram from various CuO combinations

After studying the results another system of interest is Ta-CuO. Tantalum’s poor performance at

1.2 km/s in the Naval Surface Warfare Center apparatus as outlined in Chapter 2.2 and its extremely high

boiling point at 3007 oC second only to tungsten at 3414 oC made even a moderately exothermic reaction

seem unlikely [14]. However, comparing the results the Ta-THV mixture released 645 J/g of chemical

energy while the Ta-CuO mixture yielded 1803 J/g. With the energetic output increasing by a factor of 3

the most reasonable conclusion is that the oxidation of tantalum is necessary and does occur to achieve a

reasonable level of energy output. This observation is also apparent in the Ta-B4C system as discussed in

Chapter 4.11.

43

4.8 Tungsten-Zinc-Zirconium Systems in Air

An intermetallic mixture comprised of tungsten, zinc, and zirconium was extensively tested by

varying the weight percentages of tungsten, zinc, or zirconium in the same constant volume process as

discussed in Chapter 4.7. Each powdered metal was selected so as to provide an important component to

the overall energetic system. A -325 mesh (44 μ) powdered tungsten, -325 mesh powdered zinc, and a 2-3

μ powdered zirconium mixed in different percentages created ten different W-Zn-Zr subsystems with the

addition of a few W-Zr subsystems for examination. As an extremely dense metal, tungsten provided the

mass necessary to increase the kinetic energy when confined to a small volume of the sample cavity in

each bullet. The addition of zinc is thought to increase the production of gas following the impact,

ultimately leading to higher measurable overpressures. Of the transition metals zinc has one of the lowest

melting points at 420 oC and boiling points at 907 oC while zirconium has a much higher melting point of

1854 oC and boiling point of 4409 oC and tungsten even higher with a melting point of 3414 oC and a

boiling point of 5555 oC [14]. Zinc is also known to oxidize into forms such as zinc oxide (ZnO) and zinc

nitrate (N2O6Zn), which made it an important component to the experimental system. Lastly, zirconium

has been commonly tested in other energetic applications due to its ability to readily react with the

oxygen forming zirconium(IV) oxide (ZrO2) making it one of the top performing energetic metals. Also

of interest in the tri-metallic system is whether tungsten reacts either with the other metals or with the

environment (nitrogen or oxygen). Thus, a W-Zn-Zr system has the potential to be a highly energetic

system given our intent to combined density and gas production with an exothermic reaction. Figure 4.9 displays the results from dozens of W-Zn-Zr subsystems where variations of each

constituent contributed to a change in the total energy deposited. The differences in the total energy

amount to at most 100 joules making drawing conclusions challenging. A 18/33/50% of W-Zn-Zr

respectively resulted in the highest performing energetic combination for this system averaging a total

energy output of approximately 1,000 J. Unfortunately on a chemical energy basis, the relatively close

proximity of the results make distinguishing the effects of consentient combinations on chemical energy

output difficult.

A better metric for comparison is to consider the energy output per unit mass for each system. Figure 4.10

below highlights the results from the ten W-Zn-Zr or W-Zr systems. In review of W-Zn-Zr system the

most apparent trend, above all other material variations, is that by increasing the proportion of zirconium

in the samples the system yields a higher energy output measured in joules per gram. This is observable

when comparing W-Zn-Zr 18/45/38% to 10/33/57% to 17/16/67% to 5/16/79% where each specimen

contained an equal or greater quantity of zirconium resulting in a more exothermic reaction.

44

Figure 4.9: Chemical energy release from various W-Zn-Zr combinations

Figure 4.10: Energy release per gram from various W-Zn-Zr combinations

45

Figure 4.11: XRD results from various W-Zn-Zr 17/16/67% combinations (Test# 31, 43, 58, 51)

Figure 4.11 is the XRD analysis for W-Zn-Zr 17/16/67% as numerous tests of this system

resulted in a large collection of residue allowing the use of the .50 in. diameter quartz zero background

holder. Although challenging to discern from multiple shared phase angles, the XRD analysis detected

possible traces of both ZnO and Zr0.5W0.5O2, which offered insight into how this system performed

slightly better than others. In an effort to better understand whether tungsten reacts exothermically to form

either Zr0.5W0.5O2 or WO2 or WO3 and contribute to the measured quasi-static pressure, a series of Zr-W

tests were conducted allowing for the isolation of any potential tungsten energy release. Figure 4.12

depicts the results of 2-3 µ powdered zirconium and <1 µ powdered tungsten mixed in various ratios and

comparing the theoretical energy release of the zirconium metal in the form of:

Zr (s) + O2 (s) → ZrO2 (s) + 1101 KJ (4.6)

Results indicate that for the 50/50 and 40/60 Zr-W systems that the actual release of energy is only 55%

of the theoretical zirconium energy release. However, for the Zr-W ball milled specimen the outcome was

surprisingly different as the measured results exceed the theoretical results by 31 joules. Taking into

46

account the fact that the zirconium in the Zr-W ball milled specimen is not going to release an energy

equivalent to its theoretical maximum this left approximately 390 J of energy that did not originate from

the formation of ZrO2. Figure 4.13 shows the XRD analysis of the residue and although quantities of pure

tungsten were detected so were traces of Zr0.5W0.5O2 as several phase angles were not shared by any other

compounds or element. To sum up, the reaction of tungsten would require further testing to definitively

prove, yet both the XRD analysis and the recorded pressures indicate the strong likelihood that tungsten

reacts exothermically.

Figure 4.12: Comparison of the theoretical zirconium energy release to the measured Zr-W energy release

47

Figure 4.13: XRD results for a Zr-W 66/33% ball milled sample (Test#19)

4.9 Tungsten-Zinc-Hafnium Systems in Air

Similar to the W-Zn-Zr system, tungsten was replaced with hafnium and mixed in increasing

amounts for three different systems. With 1145 KJ/mol released for the formation of HfO2 compared to

1101 KJ/mol for ZrO2, the energy release using either zirconium or hafnium are very comparable yet

hafnium is twice as dense at 178.5 g/mol compared to 91.2 g/mol for zirconium. Figure 4.14 compares

and contrasts the two different experimental systems. At first glance it appears as though in some

situations zirconium outperforms hafnium while in others the opposite is true. When considering the

amounts of zirconium and hafnium in each test (i.e. there are 115 mg of hafnium versus 71 mg of

zirconium in the 18/45/37% system) and their respective energy output per gram, the results below may

not justify zirconium outperforming hafnium. Therefore, other aspects were considered.

48

Figure 4.14: Comparison of W-Zn-Hf and W-Zn-Zr experimental systems

As expected Figure 4.15 shows that the energy output per gram of zirconium exceeds that of

hafnium, thus in many cases making the W-Zn-Zr system a better choice both in terms of overall energy

output and energy to weight ratio in practical application. Due to the increased mass (300mg versus

200mg) for specimens containing hafnium, the hardened steel anvils experienced greater penetration. The

average penetration depth for a hafnium filled bullet was 5 mm compared to 1-2 mm for other specimens.

With this in mind, it’s reasonable to assume that a greater proportion of the kinetic energy is transferred

into the mechanical deformation of the anvil than to the generation of “hot spots” in the reactive material.

This less favorable energy transfer is a result of the hafnium requiring hardness greater than the 50 HRC

achieved from heat treating the 4140 steel anvils. The heat treatment of the 4140 steel proved to be a cost

effective approach to a relatively high level of hardness; however, future tests with dense metals would

require a hardness greater than 50 HRC to avoid the energy loss due to penetration.

49

Figure 4.15: Comparison of W-Zn-Hf and W-Zn-Zr systems in Joules/gram

Figure 4.16: XRD results for a W-Zn-Hf 5/16/79% sample (Test#39)

50

Similar to the W-Zn-Zr investigation, part of the interest with the W-Zn-Hf system was to

determine whether the increased exothermic nature of hafnium over zirconium could create an

environment and achieve a temperature or activation energy that would yield a tungsten reaction. Unlike

the XRD results for W-Zn-Zr, the W-Zn-Hf analysis did not show similar formations of tungsten oxides

or indicators of ZnO (Figure 4.16). Again, the presence of these compounds is still likely, yet the “dirty”

intensity-phase plots with numerous overlapping phase angles and materials exhibiting multiple, small

intensity peaks made post processing challenging and often inconclusive for some materials.

4.10 Potassium Perchlorate Systems in Air

Potassium perchlorate, KClO4, is a white crystalline solid that is widely used in explosives and

propellants due to its ability to readily transfer oxygen to reactive metals resulting in significant

exothermic reactions. Potassium perchlorate itself is relatively stable, yet the additional oxygen atoms

create a system that enhances the oxidation above that of air with 21% oxygen by volume. Oxidizers such

as potassium chlorate, KClO3, are available and oxidize very readily. Since potassium perchlorate has an

activation energy 50% greater than that of potassium chlorate, it is a much more stable and safe oxidizer

to handle in a university laboratory setting [15]. Figure 4.17 serves as an excellent example of where

hafnium tested in air is compared to a Hf-KClO4 system tested in air. With only 47% hafnium by mass in

the Hf-KClO4 mixture (149mg) compared to the pure hafnium (313 mg) system, it’s apparent that the

potassium perchlorate significantly enhances the oxidation of hafnium in the formation of hafnium oxide,

HfO2.

Figure 4.17: Energy release of hafnium versus a Hf-KClO4 system

51

Using results from Chapter 2.2 as a reasonable reference the graphical summary in Figure 4.18

and Figure 4.19 are interesting in that tantalum demonstrates a moderate level of performance, which is

unusual given previously published results as referenced in Chapter 2.2 where zirconium, tantalum,

tungsten, and hafnium underwent similar testing mixed with various fluoropolymers. To better understand

the reaction process of KClO4 with the various metals, the Hf-KClO4 system residue, the most exothermic

of this series, was analyzed to determine reaction products using X-ray diffraction. The results in Figure

4.20 show that HfO2, KCl, and KO2 are likely products and primary contributors to the measured

chemical energy release of this system.

Proposed stoichiometric system reaction for chemical mixing:

2Hf (s) + KClO4 (s) → KCl (s) + 2HfO2 (s) + 2293 KJ (4.7)

Figure 4.18: Chemical energy release for various KClO4 systems

52

Figure 4.19: Energy release per gram for various KClO4 systems

With the results from Figure 4.20 indicating an additional, unsuspecting product, KO2, the equation below

provides an explanation. Energy transferred from the impact and the chemical reaction of hafnium could

likely result in the dissociation of KClO4 into KO2(s) and ClO2(g).

Plausible balanced system reactions given XRD results:

3Hf (s) + KClO4 (s) + O2 (g) → KCl (s) + 3HfO2 (s) + 3438 KJ (4.8)

392 KJ + KClO4 (s) → KO2 (s) + ClO2 (g) (4.9)

53

Figure 4.20: XRD results for the Hf-KClO4 system (Test #72)

Given that the Hf-KClO4 system had an average of 207 mg for the two tests examined, the

maximum theoretical chemical energy release based on the plausible reaction above would yield 960 J.

This conclusion seems reasonable as energy losses such as those discussed in Chapter 3.1 and possible

secondary endothermic reactions reduce that value to approximately 572 J as seen in Figure 4.18.

Unlike the Ta-CuO system, Ta-KClO4 performs unsuspectingly well and better than the Zr-

KClO4 in terms of total energy output. If the tantalum were to fully oxidize into Ta2O5, the reaction would

yield 2046 KJ/mol in comparison to 1145 KJ/mol for complete oxidation of zirconium into ZrO2.

Although the tantalum system outperformed the hafnium system, it was not by a factor of 2 as the

theoretical case would indicate for a complete reaction. Therefore, the formation of Ta2O5 in significant

amounts is unlikely and was not detected in the XRD analysis as seen in Figure 4.21. In contrast, unique

phase angles for TaN and TaO were apparent and demonstrated the likelihood of these compounds as

reaction products. According to S.P. Garb et al. in The O-Ta (Oxygen-Tantalum) System the formation of

tantalum and oxygen in the metastable phase TaO is typically only found in kinetically influenced

processes. In fact, any form outside of the stable Ta2O5 requires such an influence [16]. Since TaO is not

the most stable combination of tantalum and oxygen, it requires 251 KJ/mol to form from its elements

54

while TaN yields 251KJ/mol during the reaction. At 3433 J or 621 KJ/mol of tantalum (reactant), the Ta-

KClO4 system releases enough energy to initiate the endothermic formation of TaO.

Proposed stoichiometric system reaction for chemical mixing:

8Ta (s) + 5KClO4 (s) → 4Ta2O5 (s) + 5KCl (s) + 8202 KJ (4.10)

Plausible unbalanced system given XRD analysis and experimental results:

Ta (s) + KClO4 (s) + (O2 (g) +3.76N2 (g)) → O2 (g) + KCl (s)

+ TaN (s) + Energy (4.11)

Energy + Ta (s) + O2 (g) → TaO (s) (4.12)

Figure 4.21: XRD results for the Ta-KClO4 system (Test #57)

55

4.11 Boron Carbide Systems

Boron carbide (B4C) is another system of interest and the one most extensively studied in this

research. Boron carbide is a unique material since it exhibits extreme hardness, resistance to chemical

agents, and a low specific weight creating numerous practical applications such as bullet proof vests, tank

armor, and coatings for cutting tools. Boron carbide is also known to increase its levels of oxidation with

an increase in temperature making it unsuitable for some practical applications but interesting for our

purposes [17]. Figure 4.22 shows only residual amounts of nitration while the primary energy release

originates from the moderate level of oxidation in air and enhanced levels in a 40% oxygen environment.

At 2237 J in a 40% oxygen environment the boron carbide energy release is 69% of its maximum

theoretical value of 3232 J compared to only 300 J of energy release in air at 9% of the theoretical energy

release. The energy release here is significantly less in air than those discussed in Chapter 4.7 for the CuO

systems. One hypothesis is that the energy required to break apart the boron carbide molecules and fully

oxidize the boron and carbon atoms is not sufficient at 1.2 km/s. However, in limited amounts in air and

at a greater percentage in 40% oxygen, the 4-7 µ boron carbide powder oxidation most likely occurs in

the form of:

B4C (s) + 4O2 (g) → 2B2O3 (s) + CO2 (g) + 2878 KJ (4.13)

Figure 4.22: Chemical energy release from various boron carbide combinations

56

Figure 4.23: Chemical energy release from various boron carbide combinations in air

Figure 4.24: Chemical energy release per gram from various boron carbide combinations in air

57

Reviewing the results from Figure 4.23 and Figure 4.24, the boron carbide reaction with oxygen

alone does not account for the full energy release of each respective system. With boron carbide reaching

only 10% of its theoretical value in air, the expected 4852 J/g of energy output for boron carbide was used

to calculate the contribution of boron carbide in each system assuming the boron reacted solely with air at

10% of complete reaciton (Figure 4.25). In each case the metallic component of the titanium, zirconium,

and hafnium boron carbide systems oxidizes or nitrates in air or forms borides and releases relatively

large amounts of energy while the refractory metals tungsten and tantalum show similar promise with

lesser energy output per mole.

Figure 4.25: Chemical energy release for boron carbide systems based on experimental results

Tantalum and tungsten with their strong interatomic bonding and high melting temperatures of

3017 oC and 3414 oC respectively tend to resist chemical reactivity until extremely high temperatures are

reached [18]. This result is apparent in Figure 4.25 where tantalum and tungsten performed relatively

poorly in comparison to other systems. Even a substitution of <1 µ for < 44 µ tungsten only slightly

improved the chemical contribution of tungsten while titanium, zirconium, and hafnium boron carbide

systems demonstrated significant energy release. Further, hafnium and titanium boron carbide were

58

among the top five performers in terms of energy output and zirconium of all systems examined in this

paper and titanium boron carbide were the top two performers in terms of energy output per mass. A

complete discussion of top performers is found in Chapter 5.

The relatively high exothermic nature of the Ti-B4C system is attributed to the highly reactive

nature of both titanium and boron carbide at elevated temperatures. As discussed previously, boron

carbide oxidizes readily at elevated temperatures. Similarly, titanium exhibits increased levels of chemical

reactivity in higher temperature regimes [18]. XRD analysis for Ti-B4C in air contained unique phase

angles for B2O3 and TiO2 in the residue with minor traces of C3N4 and Ti2N. Of interest is the 40%

oxygen system for Ti-B4C as several distinct phase angles are likely the result of Ti3B4 formation in the

products while peak intensities for Ti3B4 were not detected in air (Figure 4.26). Ti2O3 has a heat of

formation of -1521 KJ/mol while TiO2 has a value of -944 KJ/mol both in crystalline form. Moreover,

B2O3 has a value of -1274 KJ/mol, BN a value of -251KJ/mol, TiB2 a value of -279 KJ/mol, TiC a value

of -184 KJ/mol, and Ti2N a value of -122 KJ/mol. To add to the uniqueness of titanium, it is one of the

few metals that burns in nitrogen at temperatures of 800 oC [19]. Thus, the exothermic nature of most all

the possible products increased the probability that a large percentage of the prepared sample would react

exothermically either with the surrounding environment or as a binary system.

Figure 4.26: XRD results for the Ti-B4C system in 40% oxygen (Test #108)

59

To examine this process further the entire boron carbide system was tested in a 100% nitrogen

environment as well as in air. Figure 4.27 shows minor, yet measurable energy output for each boron

carbide system in nitrogen. The pure boron carbide test demonstrates that various nitrides such as BN and

C3N4 are possible as chemical reactions are measured. Unfortunately, BN shares multiple phase angles

with that of copper making assurance of its presence impractical with XRD analysis. Based on the

experimental pressure results and the XRD analysis in Figure 4.26 and Figures 4.29-4.34 the B4C reacted

primarily with the oxygen forming B2O3 (s) and CO2 (g) (assumed but not confirmed) for all tests

conducted in air. C3N4 is an endothermic reaction and the phase angles which represent C3N4 are shared

with B2O3 and PbO making a definitive conclusion impossible again through XRD analysis. However, G.

Goglio explained in “State of Art trends in bulk carbon nitride synthesis” that the nitration of carbon can

occur through various mechanosynthesis processes where “[t]he involved mechanisms are related to the

high intergranular pressure associated with high temperature due to collisions and frictions phenomena

during the grinding process. In this sense, despite of the fact that experimental pressure and temperature

conditions are moderate, the local pressure and temperature are very high which allows classifying this

process as a high pressure-like” [20]. The paper goes on further to discuss in high energy ball milling as a

viable mechanosynthesis process for the formation of C3N4 as well as the influence of dynamic pressures.

Figure 4.27: Chemical energy release contributions for boron carbide compared to the metallic component

60

Estimates place a reactive material bullet travelling at 1.2 km/s experiencing up to 62 MPa or 9,000 psi at

the point of impact on the anvil. Thus, the localized pressure, energy, and friction of B4C particles at the

point of impact in a nitrogen heavy environment (air) could yield C3N4 or other variation of the carbon

nitride. In contrast, if the reaction of nitrogen and boron were to proceed as follows without the formation

of C3N4:

B4C (s) + 2N2 (g) → 4BN (s) + C + 941 KJ (4.14)

the results in Figure 4.27 show that BN would only be performing at 9% of its theoretical energy release

of 1038 J for a 61 mg sample. Since all the binary boron carbide systems exceed the pure boron carbide

system in energy release, metallic borides, carbides, and nitrides are conceivable products. As for the case

of pure hafnium, the exothermic formation of a hafnium nitride can be ruled out as pure hafnium was

tested in 100% nitrogen yielding no measurable energy release (Figure 4.28). Figure 4.28 also shows that

at 1244 J the combustion of hafnium in a 40% oxygen rich environment is 62% of the theoretical energy

release of 2008 J while only 13% in air at 257 J. Referring back to previous discussions in Chapters 4.7

and 4.11that either through a 40% oxygen rich environment or the addition of powdered oxidizers with

the metal, high-levels (>60%) reaction efficiencies can be achieved.

Figure 4.28: Chemical energy release of hafnium in various environments

61

Given the current post processing methods and the limited amount of residue to process, the

following set of unbalanced global equations are plausible reaction systems:

Ti-B4C

Ti (s) + B4C (s) + (O2 (g) +3.76N2 (g)) → TiB2 (s) + B2O3 (s)

+ TiO2 (s)+ BN (s) + C3N4 (s) + Ti2N (s) + CO2 (g) + Energy (4.15)

Ta-B4C

Ta (s) + B4C (s) + (O2 (g) +3.76N2 (g)) → TaC (s) +Ta2O5 (s) + B2O3 (s)

+ BN (s) + CO2 (g) + C3N4 (s) + Energy (4.16)

W-B4C

W (s) + B4C (s) + (O2 (g) +3.76N2 (g)) → WO3 (s) + B2O3 (s) + BN (s) + CO2 (g)

+ C3N4 (s) + Energy (4.17)

Zr-B4C

Zr (s) + B4C (s) + (O2 (g) +3.76N2 (g)) → ZrO2 (s) + B2O3 (s) + BN (s) + CO2 (g)

+ C3N4 (s) + Energy (4.18)

Hf-B4C

Hf(s) + B4C (s) + (O2 (g) +3.76N2 (g)) → HfO2 (s) + HfC (s) + B2O3 (s)

+ BN (s) + CO2 (g) + C3N4 (s) + Energy (4.19)

62

Figure 4.29: XRD results for the Ti-B4C system in air (Test #80)

Figure 4.30: XRD results for the Ta-B4C system in air (Test #88)

63

Figure 4.31: XRD results for the Zr-B4C system in air (Test #42)

Figure 4.32: XRD results for the W-B4C system in air (Test #82)

64

Figure 4.33: XRD results for the Hf-B4C system in air (Test #41)

Figure 4.34: XRD results for the Hf-B4C system in 100% nitrogen (Test #93)

65

In review of all boron carbide systems and environments it is apparent that oxidation is still the

greatest contributor to exothermic reactions. Figure 4.35 compares all environments and shows that

doubling the oxygen content from air at 21% oxygen to a 40% oxygen environment doubles the energy

output of titanium, zirconium, and hafnium boron carbide systems. Figure 4.35 also shows that the

nitration levels are only minor contributors at best to the overall energy release. With the high level of

reactivity in the 40% environment tests, the measured pressures were surprisingly high in the range of 20-

30 psig, which approached or exceeded the design limit for some of the pressure transducers. Therefore,

further testing in enriched oxygen environments would require the use of pressure transducers with a

greater pressure range.

Figure 4.35: Chemical energy release of all tested boron carbide systems in various environments

66

4.12 Bismuth Oxide Systems in Air

Experimentation with bismuth oxide system provided an additional opportunity to investigate

tantalum and tungsten in relation to the previous set of systems. Results from tests conducted with

tungsten, tantalum, and hafnium bismuth oxide are tabulated in Figure 4.36. The two extremes are of no

surprise in that tungsten performed poorly with little to no oxidation while the oxidation of hafnium

yielded the largest energy release with just over 400 J of measured chemical energy.

Figure 4.36: Chemical energy release from various bismuth oxide combinations in air

Of interest, again, is the high-energy release from the Ta- Bi2O3 system, which rivals Hf-Bi2O3.

Although previous XRD analysis on tantalum systems did not reveal the formation of tantalum oxides,

it’s possible that both tantalum and tungsten combust and assume amorphous structures. Unfortunately,

non-crystalline structures are undetectable using XRD. Nonetheless, the performance of tantalum

suggests that tantalum readily oxidized yielding a significant energy output relative to Hf-Bi2O3.

Plausible reaction given experimental pressure results:

6Ta (s) + 5Bi2O3 (s) → 3Ta2O5 (s) + 10Bi (s) + 3269 KJ (4.20)

67

Processing the Hf-Bi2O3, the most exothermic reaction of the bismuth oxide systems, provided an

understanding as to whether the reaction behaved as expected. Figure 4.37 displays the XRD results and

as expected HfO2 and Bi were detected in the residue with small traces of Bi2O3 that failed to react.

Plausible reaction given experimental pressure results:

3Hf (s) + 2Bi2O3 (s) → 3HfO2 (s) + 4Bi (s) + 2286 KJ (4.21)

Figure 4.37: XRD results for the Hf-Bi2O3 system (Test #78)

68

Chapter 5

Conclusions

5.1 Recommendations for Future Studies

A wide range of binary and tertiary reactive material systems were proposed and experimentally

tested in the scaled combustion facility. The facility demonstrated a capacity to withstand scores of tests

and provide a high level of experimental repeatability despite specimen samples only ranging from 100-

300 mg in mass. The facility also performed well under the different environmental conditions.

Additional testing in 40% oxygen would require the use of flame resistant material over the two

polycarbonate windows or their replacement altogether. The enhanced combustion during these tests

resulted in the superficial burning of the windows.

Of the 110 tested reactive material and inert systems, tungsten was an element of interest as

significant levels of combustion are rare. In most cases a reduction in particle size with the <1 µ over the

< 44µ tungsten powder or an alternative oxidizing agent created no significant improvements. The W-Zn-

Zr 18/33/50% system’s arrangement provided the optimal amount of each primary element maximizing

combustion. Again, XRD analysis on the residue was not conclusive as the presence Zr0.5W0.5O2 or other

tungsten oxides were not definitive and the formation of ZnO (g) is undetectable, which could attribute to

the high-level of performance. The one exception to this trend of inclusiveness was the results for the

single Zr-W (66/33%) ball milled specimen. This binary system demonstrated a level of performance that

could not be explained by the zirconium alone as the energy release exceeded zirconium’s theoretical

maximum. Further tests with ball milled specimens of different tungsten and zirconium ratios could

generate supporting evidence that high impact alloying is the sample preparation “ingredient” required to

achieve higher levels of tungsten reactivity.

Further, additional post processing on the Ti-B4C residue by X-ray fluorescence or chemical

detection should assist in determining the different products as XRD failed to detect non-crystalline

structures and residue samples with multiple products became “crowded” and complicated to process.

69

5.2 Best Performing Systems

Figure 4.38 and 4.39 display the top ten systems in terms of energy output in joules and energy

output per mass in joules/gram. The results herein provide a reference for follow-on research into

dissecting each system and understanding the specifics into what makes these optimal.

Figure 5.1: Top 10 performers in terms of chemical energy (J)

70

Figure 5.2: Top 10 performers in terms of chemical energy per mass (J/g)

71

References

1. Committee on Advanced Energetic Materials and Manufacturing Technologies. Advanced

Energetic Materials. National Academy of Sciences. The National Academies Press. 2004. 20-23.

2. Kinney, Gilbert. Explosive Shocks in Air. United States Naval Postgraduate School, Monterey

California. The Macmillan Company, 1962.

3. Ames, Richard and Samuel Waggener. “Reaction Efficiencies for Impact-Initiated Energetic

Materials.” Naval Surface Warfare Center, Dahlgren Division. Proceedings of the 32nd

International Pyrotechnics Seminar. Jun 2005.

4. Lee, R.J. W. Mock, J.R. Carney, W.H. Holt, G.I. Pangilinan, R.M. Gamache, J.M. Boteler, D.G.

Bohl, J. Drotar, and G.W. Lawrence. “Reactive Materials Studies.” Naval Surface Warfare Center,

Indian Head & Dahlgren Division.

5. Felts, Josh. “Experimental Investigations for Initiating Reaction of High Speed Aluminum in

Gaseous and Liquid H2O.” Master’s Thesis in Mechanical Engineering at the University of Illinois

at Urbana-Champaign. 2006.

6. Ames, Richard. “Vented Chamber Calorimetry.” Naval Surface Warfare Center, Dahlgren

Division. Proceedings of the 43rd AIAA Aerospace Science Meeting. Jan 2005.

7. Headquarters, Department of the Army. TM 43-0001-28. Army Ammunition Data Sheet. Apr 1994.

8. Ali, Mudasir, Michael Hernandez, Laura Nagel, and David Tersch. “Mini Pig: Design of a Scaled

Reactive Material Test Apparatus.” Senior design final project in Mechanical Engineering at the

University of Illinois at Urbana-Champaign, Dec 2006.

9. Lee, Richard Dr. Dynamics & Diagnostics Division, Research & Technology Department, Naval

Surface Warfare Center, Indian Head Division. Phone conversation on 12 Feb 2010.

10. Accurate Arms Company. Accurate Smokeless Powder Loading Guide. Wolfe Publishing

Company, 1994.

11. Gordienko, S.P. “Thermodynamic Analysis of the Reaction of Titanium with Boron Carbide in a

Self-Propagating High-Temperature Synthesis Regime.” Powder Metallurgy and Metal Ceramics,

Vol 38, Nos. 3-4, 1999.

12. Blount, Inc. Sporting Equipment Division. Speer Reloading Manual Rifle and Pistol. Fourth

Printing, Nov 2001.

13. Speakman, Scott. “Basics of X-Ray Diffraction: Self User Training for the X-Ray Diffraction

SEF.” Power Point slides prepared by author and accessed at http://prism.mit.edu/xray. Nov 2010.

72

14. The Chemical Rubber Company. CRC Handbook of Chemistry and Physics: 86th Edition.

Chemical Rubber Publishing Company. 2005.

15. Journal of Pyrotechnics, Inc. Pyrotechnic Chemistry: Pyrotechnic Literature Series Version 4.

Journal of Pyrotechnics, Inc. 2004.

16. Garg, S.P., N. Krishnamurthy, A. Awasthi Bhabha Atomic Research Centre, and M. Venkatraman

Naval Chemical and Metallurgical Laboratory. “The O-Ta (Oxygen-Tantalum) System.” Journal

of Phase Equilibria Vol. 17 No. 1, 1996.

17. Li, Y.Q. and T. Qiu. “Oxidation behavior of boron carbide powder.” Material Science and

Engineering A 444 (2007) 184-191. 2006.

18. Callister, William. Materials Science and Engineering an Introduction: Fifth Edition. Von

Hoffman Press. 2000.

19. Rossi, Auguste. “On the Manufacture of Ferro-Alloys in General and of Ferro-Titanium in

particular in the Electric Furnace.” Electrochemcial Industry. Volume I, Nov 1903.

20. Goglio, Graziella, Denis Foy, and Gerard Demazeau. “State of Art and recent trends in bulk

carbon nitrides synthesis.” Materials Science and Engineering R 58, 195-227. 2008.

73

Appendix A:

Sample Preparation Equations

System mixtures were based on the following proposed reactions:

Copper(II) Oxide Systems

2Al (s) + 3CuO (s) → Al2O3 (s) + 3Cu (s) + 1204 KJ

W (s) + CuO (s) → WO3 (s) + 3Cu (s) + 686 KJ

2Ta (s) + 5CuO (s) → Ta2O5 (s) + 3Cu (s) + 1260 KJ

2Ti (s) + 2CuO (s) → TiO2 (s) + 2Cu (s) + 629 KJ

Zr (s) + 2CuO (s) → ZrO2 (s) + 2Cu (s) + 786 KJ

Hf (s) + 2CuO (s) → HfO2 (s) + 2Cu (s) + 830 KJ

Boron Carbide Systems

3Ti (s) + B4C (s) → 2TiB2 (s) + TiC (s) + 680 KJ

3Zr(s) + B4C (s) → 2ZrB2 (s) + ZrC (s) + 779 KJ

3Hf(s) + B4C (s) → 2HfB2 (s) + HfC (s) + Energy

3W(s) + B4C (s) → 2WB2 (s) + WC (s) + Energy

74

3Ta(s) + B4C (s) → 2TaB2 (s) + TaC (s) + Energy

Potassiumperchlorate Systems

4W (s) + 3KClO4 (s) → WO3 (s) + 3KCl (s) + 854 KJ

2Hf (s) + KClO4 (s) → 2HfO2 (s) + KCl (s) + 2293 KJ

8Ta (s) + 5KClO4 (s) → 4Ta2O5 (s) + 5KCl (s) + 8202 KJ

2Zr (s) + KClO4 (s) → 2ZrO2 (s) + KCl (s) + 2205 KJ

Bismuth Oxide Systems

W (s) + Bi2O3 (s) → WO3 (s) + 2Bi (s) + 269 KJ

3Hf (s) + 2Bi2O3 (s) → 3HfO2 (s) + 4Bi (s) + 2286 KJ

6Ta (s) + 5Bi2O3 (s) → 3Ta2O5 (s) + 10Bi (s) + 3269 KJ

75

Appendix B:

Complete Test Results

1.4

Vol

ume(

cc)

0.03

4847

**25

gra

ins*

* m

eans

vel

ocity

mea

sure

men

t fai

led

TS

WZ

ZB

llM

()

Mat

eria

l Ve

loci

ty

Velo

city

G

15G

45K

li25

G15

G45

Kli

25G

15G

45K

li25

G15

G45

Kli

25T

lE(J)

Kii

E(J)

Chem

ical

CE

(J)/

Ratio

of S

pecific

Hea

tEn

ergy

Rel

ease

(Jou

les)

Impu

lse F

S(PS

I-ms)

Even

t Tim

e (m

s)Pe

ak P

ress

ure

(PSI

-G)

Test

Syst

emW

ZnZr

Bulle

t Mas

s (g)

Mat

eria

l M

ass (

mg)

Velo

city

(ft/s

)Ve

loci

ty

(m/s

)Ge

ms-

15Ge

ms-

45Ku

lite-

25Ge

ms-

15Ge

ms-

45Ku

lite-

25Ge

ms-

15Ge

ms-

45Ku

lite-

25Ge

ms-

15Ge

ms-

45Ku

lite

25To

tal E

nerg

y (J)

Kine

tic E

nerg

y (J)

Chem

ical

En

ergy

(J)

CE(J)

/g

1W

-Zn-

Zr17

.50%

33.0

%49

.50%

1.29

0719

1.7

3724

1135

2453

2507

2522

475

475

475

13.8

713

.81

13.9

213

2813

2313

3413

2933

099

952

092

W-Z

n-Zr

17.5

0%33

.0%

49.5

0%1.

2938

201.

433

0910

0919

4619

5119

6853

453

266

510

.63

10.5

110

.61

1018

1007

1016

1014

261

752

3735

2W

ZnZr

17.5

0%33

.0%

49.5

0%1 .

2938

201.

433

0910

0919

4619

5119

6853

453

266

510

.63

10.5

110

.61

1018

1007

1016

1014

261

752

3735

3W

-Zn-

Zr17

.46%

45.3

2%37

.39%

1.30

5220

0.4

3850

1173

2218

2260

2277

487

487

533

13.8

313

.66

13.8

013

2513

0913

2213

1835

696

248

014

W-Z

n-Zr

17.4

6%45

.32%

37.3

9%1.

3046

205.

235

9810

9421

3621

4421

9952

951

994

812

.11

11.8

511

.48

1160

1136

1100

1132

310

822

4007

8W

-Zn-

Zr5.

06%

16.0

%78

.94%

1.25

7616

4.6

3718

1133

2810

2865

2864

635

637

713

13.6

913

.47

13.4

513

1112

9012

8912

9732

097

659

318

W-Z

n-Zr

5.06

%16

.0%

78.9

4%1.

2576

164.

637

1811

3328

1028

6528

6463

563

771

313

. 69

13.4

713

. 45

1311

1290

1289

1297

320

976

5931

35W

-Zn-

Zr5.

06%

16.0

%78

.94%

1.29

6917

2.5

3902

1189

2914

2950

2966

655

647

721

13.1

113

.02

13.1

012

5612

4712

5512

5336

488

951

5285

W-Z

n-Zr

5.06

%16

.0%

78.9

4%1.

279

176.

539

7912

1330

1631

0531

1164

965

571

314

.27

14.2

714

.34

1367

1367

1374

1369

373

996

5642

9W

-Zn-

Zr10

06%

3316

%56

78%

127

9117

67

3573

1089

2756

2796

2802

624

618

760

1290

1270

1279

1236

1217

1226

1226

301

925

5236

9W

-Zn-

Zr10

.06%

33.1

6%56

.78%

1.27

9117

6.7

3573

1089

2756

2796

2802

624

618

760

12. 9

012

.70

12.7

912

3612

1712

2612

2630

192

552

3638

W-Z

n-Zr

10.0

6%33

.16%

56.7

8%1.

291

188.

338

2311

6828

5428

8528

9964

764

672

612

.79

12.6

712

.82

1225

1213

1228

1222

350

873

4635

87W

-Zn-

Zr10

.06%

33.1

6%56

.78%

1.30

4118

8.3

4057

1237

2683

2713

2722

630

625

713

13.0

312

.81

13.0

012

4812

2712

4512

4039

684

444

8310

W-Z

n-Zr

505

%45

4%49

56%

130

0119

48

3895

1187

2808

2831

2840

639

626

703

1308

1286

1297

1253

1232

1242

1242

364

879

4511

10W

-Zn-

Zr5.

05%

45.4

%49

.56%

1.30

0119

4.8

3895

1187

2808

2831

2840

639

626

703

13.0

812

.86

12. 9

712

5312

3212

4212

4236

487

945

1136

W-Z

n-Zr

5.05

%45

.4%

49.5

6%1.

2983

198.

339

7312

1128

9829

4729

6166

265

773

813

.14

12.9

913

.10

1259

1245

1255

1253

378

875

4413

11W

-Zn-

Zr10

.01%

40.5

%49

.44%

1.30

6920

6.0

3829

1167

2834

2895

2900

602

603

674

14.0

313

.95

13.8

813

4513

3613

2913

3735

398

447

7437

W-Z

n-Zr

1001

%40

5%49

44%

129

0718

96

3876

1182

2820

2849

2868

675

665

774

1228

1225

1223

1176

1173

1172

1174

358

816

4304

37W

- Zn-

Zr10

.01%

40.5

%49

.44%

1.29

0718

9.6

3876

1182

2820

2849

2868

675

665

774

12.2

812

.25

12.2

311

7611

7311

7211

7435

881

643

0412

W-Z

n-Zr

17.4

6%16

.0%

66.5

0%1.

2874

188.

437

6611

4811

9214

2312

7626

266

466

416

.43

15.7

916

.32

1574

1513

1564

1550

337

1214

6441

31W

-Zn-

Zr17

.46%

16.0

%66

.50%

1.28

9419

0.1

3908

1191

3143

3219

3230

694

690

761

13.9

113

.88

13.9

013

3313

3013

3213

3236

396

950

9548

WZn

Zr17

46%

160%

6650

%1

295

193

340

2412

2733

2534

0934

1671

970

579

414

0914

1414

1213

5013

5513

5213

5238

796

649

9548

W- Z

n-Zr

17.4

6%16

.0%

66.5

0%1 .

295

193.

340

2412

2733

2534

0934

1671

970

579

414

. 09

14.1

414

. 12

1350

1355

1352

1352

387

966

4995

34W

-Zn-

Zr17

.46%

16.0

%66

.50%

1.29

1919

0.3

4031

1229

3596

3605

3615

794

754

822

13.6

913

.62

13.7

213

1213

0513

1413

1038

792

348

5151

W-Z

n-Zr

17.4

6%16

.0%

66.5

0%1.

2914

190.

039

4712

0331

0731

4631

5270

569

677

513

.44

13.3

613

.30

1287

1280

1275

1281

371

910

4788

55W

ZnZr

(14

8%M

C)17

46%

1600

%66

50%

128

9219

00

4084

1245

2451

2477

2496

584

579

651

1230

1224

1230

1178

1173

1178

1176

397

780

4105

55W

-Zn-

Zr (1

4.8%

MC)

17.4

6%16

.00%

66.5

0%1.

2892

190.

040

8412

4524

5124

7724

9658

457

965

112

.30

12.2

412

.30

1178

1173

1178

1176

397

780

4105

68W

-Zn-

Zr (1

4.9%

MC)

17.4

7%16

.00%

66.5

3%1.

2847

189.

440

4412

3323

0323

2023

3657

457

066

311

.77

11.6

911

.76

1127

1120

1127

1125

388

737

3892

56W

-Zn-

Zr (7

.0%

MC)

17.4

6%16

.00%

66.5

0%1.

2886

190.

025

gra

ins

1220

2983

3037

3054

670

666

746

13.1

013

.12

13.0

212

5512

5712

4712

5338

187

245

9170

WZn

Zr(7

0%M

C)17

47%

1600

%66

53%

128

5018

97

4050

1235

2303

2320

2336

574

570

663

1371

1371

1173

1313

1313

1123

1250

389

861

4538

70W

- Zn-

Zr (7

.0%

MC)

17.4

7%16

.00%

66.5

3%1 .

2850

189.

740

5012

3523

0323

2023

3657

457

066

313

. 71

13.7

111

. 73

1313

1313

1123

1250

389

861

4538

62W

-Zn-

Zr (3

.5%

MC)

17.4

6%16

.00%

66.5

0%1.

2827

190.

139

9812

1925

4725

6325

7661

862

169

312

.11

12.1

212

.04

1160

1161

1154

1158

378

780

4102

71W

-Zn-

Zr (3

.5%

MC)

17.4

7%16

.00%

66.5

3%1.

2868

189.

540

7712

4329

4029

9730

0066

767

072

913

.17

13.1

713

.10

1262

1262

1255

1259

395

865

4563

86W

ZnZr

(35%

MC)

1750

%16

00%

6650

%1

3206

189

539

7212

1126

4026

8426

9860

760

568

412

9012

9012

7812

3612

3512

2412

3238

484

744

7286

W- Z

n-Zr

(3.5

% M

C)17

.50%

16.0

0%66

.50%

1 .32

0618

9.5

3972

1211

2640

2684

2698

607

605

684

12. 9

012

.90

12. 7

812

3612

3512

2412

3238

484

744

7263

W-Z

n-Zr

(0%

MC)

17.4

6%16

.00%

66.5

0%1.

2867

188.

740

3112

2927

8328

3428

4564

064

474

213

.03

13.0

112

.93

1249

1247

1239

1245

386

859

4553

66W

-Zn-

Zr (0

% M

C)17

.47%

16.0

0%66

.53%

1.26

7118

9.7

3909

1192

2989

3029

3039

690

692

789

12.9

112

.92

12.8

412

3612

3812

3012

3535

787

846

26

Test

Syst

emW

ZnHf

Bulle

t Mas

s (g)

Mat

eria

l M

ass (

mg)

Velo

city

(ft/s

)Ve

loci

ty

(m/s

)Ge

ms-

15Ge

ms-

45Ku

lite-

25Ge

ms-

15Ge

ms-

45Ku

lite-

25Ge

ms-

15Ge

ms-

45Ku

lite-

25Ge

ms-

15Ge

ms-

45Ku

lite

25To

tal E

nerg

y (J)

Kine

tic E

nerg

y (J)

Chem

ical

En

ergy

(J)

CE(J)

/g

14W

ZHf

1776

%44

62%

3762

%1

4111

310

738

2911

6720

9220

7320

2858

457

364

710

6110

4910

7610

1610

0510

3110

1738

163

620

4714

W-Z

n-Hf

17.7

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738

2911

6720

9220

7320

2858

457

364

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10.4

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1016

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1031

1017

381

636

2047

17W

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1.45

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2.8

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1201

3550

3732

3732

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707

764

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4915

6715

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2612

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514

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1541

1562

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430

1082

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20W

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1.45

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3342

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3347

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771

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13.4

612

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839

8612

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2031

5831

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669

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213

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1264

1247

1262

1258

417

841

2580

Test

Syst

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ass (

g)M

ater

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Mas

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loci

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loci

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25To

tal E

nerg

y (J)

Kine

tic E

nerg

y (J)

Chem

ical

En

ergy

(J)CE

(J)/g

(g)

Mas

s (m

g)(ft/s

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Ener

gy (J

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3814

3814

2652

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475

67.

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3573

273

070

472

229

542

835

026

AL-C

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8.5

3589

1094

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541

536

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7.77

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747

305

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a no(

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5371

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833

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Rich

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512

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rain

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1.23

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2608

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634

743

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4835

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4040

1231

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1124

374

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1.23

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0.8

4031

1229

2525

2535

2546

620

610

707

11.9

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311

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gra

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556

552

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643

658

649

371

278

1811

26AL

CuO

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449

Lean

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rain

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1114

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236

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638

933

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Ti-C

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oich

1.27

0715

0.5

4070

1241

2012

2008

2019

587

596

679

9.63

9.57

9.52

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912

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3513

90Zr

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Figu

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Exp

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()

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P(P

SIG)

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l)

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Chem

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En

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871

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135

430

54

16In

ert

NA

NA

Iner

t1.

3074

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t38

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7157

857

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836

537

095

03.

843.

893.

9736

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338

137

435

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N/A

28In

ert

NA

NA

Iner

t1.

3084

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t40

2012

2563

163

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t1.

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2012

2563

163

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537

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54In

ert

NA

NA

Iner

t1.

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t40

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2763

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338

539

194

94.

184.

214.

2540

140

340

840

439

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N/A

67In

ert

NA

NA

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t1.

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5362

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165

340

240

195

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337

837

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69In

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NA

NA

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t1.

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t39

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1765

966

269

040

640

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104.

174.

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AN/A

69In

ert

NA

NA

Iner

t1.

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t39

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966

269

040

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19Zr

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665

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5Ba

ll M

ill1.

299

197.

638

7211

8030

9831

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1271

371

077

912

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12.3

212

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1198

1180

1188

1189

359

830

4199

61Zr

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40.

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3u/<

1u1.

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250.

739

7912

1331

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5431

2174

777

785

112

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12.0

011

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1156

1150

1148

1151

394

757

3019

61Zr

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40.

623u

/<1u

1.35

125

0.7

3979

1213

3100

3154

3121

747

777

851

12.0

712

.00

11.9

911

5611

5011

4811

5139

475

730

1965

Zr-W

0.5

0.5

2-3u

/<1u

1.31

122

4.2

3947

1203

2662

2660

2669

714

717

848

10.6

910

.54

10.7

210

2410

1010

2710

2037

764

428

70

30Hf

-Bi2

O3

0.12

530.

3436

Stoi

ch1.

3431

241.

139

4012

0117

8617

8918

0063

363

476

37.

727.

707.

7074

073

873

873

838

435

414

6830

HfBi

2O3

0.12

530.

3436

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ch1 .

3431

241.

139

4012

0117

8617

8918

0063

363

476

37 .

727 .

707.

7074

073

873

873

838

435

414

6878

Hf-B

i2O

30.

2576

0.44

83St

oich

1.38

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6.2

3991

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1856

1855

1868

574

575

699

9.02

8.96

9.01

864

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862

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456

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29Ta

-Bi2

O3

0.30

980.

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ch1.

3558

255.

440

3312

2918

2418

2618

3960

760

575

78.

358.

328.

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079

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740

640

115

6959

Ta- B

i2O

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3098

0.66

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oich

1.33

9124

2.1

3947

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1582

1589

1604

592

599

850

7.32

7.29

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698

385

314

1296

59Ta

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30 .

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0 .66

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1.33

9124

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1582

1589

1604

592

599

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0.30

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ch1.

3374

241.

939

5912

0715

3615

3215

5858

557

291

17.

357.

327.

3170

470

170

170

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731

513

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W-B

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oich

1.32

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2.9

3973

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1021

1021

1044

521

516

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4.93

4.98

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477

481

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386

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W-B

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0.59

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1.36

9826

8.4

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1004

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511

514

943

4.92

4.96

4.99

471

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W-B

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1 .36

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1010

1004

1035

511

514

943

4 .92

4.96

4.99

471

475

478

475

388

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2

41Hf

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0.59

0.06

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oich

1.35

3725

2.3

3953

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3529

3568

3575

767

765

854

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13.8

213

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Hf- B

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Stoi

ch1

3503

252

239

0911

9231

4132

1032

1267

568

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414

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1975

Hf- B

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239

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1351

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963

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42Zr

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0.53

110.

1073

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ch1.

2138

110.

739

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1527

8627

8327

9570

972

178

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1064

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356

712

6430

81Zr

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1073

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ch1.

2166

116.

040

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3327

4927

3227

4067

066

278

111

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11.7

511

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1139

1126

1136

1133

367

766

6607

52Ti

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040

880

1575

Stoi

ch1

1968

961

3897

1188

3037

3044

3053

686

687

782

1255

1260

1233

1202

1207

1181

1197

335

862

8965

52Ti

- B4C

0 .40

880 .

1575

Stoi

ch1.

1968

96.1

3897

1188

3037

3044

3053

686

687

782

12.5

512

.60

12.3

312

0212

0711

8111

9733

586

289

6580

Ti-B

4C0.

4088

0.15

75St

oich

1.20

2998

.840

6412

3934

5635

0535

1270

369

677

014

.55

14.9

313

.54

1394

1430

1297

1374

366

1007

1019

682

W-B

4C0.

6707

0.06

72St

oich

1.44

934

8.8

3966

1209

1716

1714

1728

616

619

748

7.49

7.45

7.52

718

714

720

717

420

297

852

83W

-B4C

075

360

0755

Stoi

chW

<1u

136

4226

63

4017

1225

1744

1743

1756

635

639

835

759

755

758

727

723

726

725

406

319

1199

83W

- B4C

0.75

360 .

0755

Stoi

ch W

<1u

1.36

4226

6.3

4017

1225

1744

1743

1756

635

639

835

7 .59

7 .55

7.58

727

723

726

725

406

319

1199

84Ta

-B4C

0.71

520.

0733

Stoi

ch T

a<2u

1.36

126

0.9

4017

1225

1772

1767

1791

633

626

939

7.25

7.14

7.29

694

684

699

692

405

287

1100

88Ta

-B4C

0.71

520.

0733

Stoi

ch T

a<2u

1.36

9424

7.8

3885

1184

1414

1417

1434

596

597

837

6.07

5.96

6.07

582

571

581

578

381

197

795

96B4

C(A

ir)0

0618

N/A

Pure

118

0261

839

7212

1115

21N/A

1537

595

06N/A

788

976

71N/A

672

642

N/A

644

643

343

300

4852

96B4

C (A

ir)0.

0618

N/A

Pure

1 .18

0261

.839

7212

1115

21N/A

1537

595.

06N/A

788.

976 .

71N/A

6.72

642

N/A

644

643

343

300

4852

100

Hf (A

ir)0.

3137

N/A

Pure

1.43

4931

3.7

3991

1217

1981

N/A

1992

711.

5N/A

949.

77.

03N/A

7.15

673

N/A

685

679

422

257

821

91W

B4C

(100

%N

2)0

7805

007

82St

oich

W<1

u1

3868

248

739

4712

0381

1N/A

802

589

N/A

579

391

N/A

391

375

N/A

375

375

242

132

532

91W

-B4C

(100

% N

2)0 .

7805

0 .07

82St

oich

W<1

u1 .

3868

248.

739

4712

0381

1N/A

802

589

N/A

579

3.91

N/A

3.91

375

N/A

375

375

242

132

532

92In

ert (

100%

N2)

N/A

N/A

Iner

t1.

308

N/A

3972

1211

340

N/A

368

335

N/A

2.41

N/A

2.43

231

N/A

233

232

232

N/A

N/A

93Hf

-B4C

(100

% N

2)0.

90.

0929

Stoi

ch.

1.36

4324

3.4

4004

1221

1054

N/A

1069

570

N/A

728

4.82

N/A

4.83

461

N/A

463

462

246

216

889

94Zr

B4C

(100

%N

2)0

5311

010

75St

oich

123

3711

30

4037

1231

596

N/A

605

351

N/A

374

374

N/A

372

358

N/A

356

357

226

131

1164

94Zr

- B4C

(100

% N

2)0 .

5311

0 .10

75St

o ich

.1 .

2337

113.

040

3712

3159

6N/A

605

351

N/A

374

3 .74

N/A

3.72

358

N/A

356

357

226

131

1164

95B4

C (1

00%

N2)

0.06

07N/A

Pure

1.18

0160

.740

3112

2942

2N/A

432

297

N/A

432

2.98

N/A

2.97

285

N/A

285

285

215

7011

46

97Ta

B4C

(100

%N

2)0

8105

008

25St

oich

137

223

64

3891

1186

617

N/A

626

357

N/A

384

367

N/A

371

352

N/A

356

354

233

121

511

97Ta

-B4C

(100

% N

2)0.

8105

0.08

25S t

oich

1.37

223

6.4

3891

1186

617

N/A

626

357

N/A

384

3 .67

N/A

3.71

352

N/A

356

354

233

121

511

98Ti

-B4C

(100

% N

2)0.

4088

0.15

76St

oich

1.22

8593

.325

gra

ins

1220

518

N/A

527

313

N/A

341

3.48

N/A

3.52

333

N/A

337

335

221

114

1227

99Hf

(100

% N

2)0.

3148

N/A

Pure

1.43

3831

4.8

3979

1213

439

N/A

451

324

N/A

358

2.71

N/A

2.74

260

N/A

263

261

255

721

101

Iner

t (50

% O

2)N/A

N/A

Iner

t1.

3089

N/A

25 g

rain

s12

2011

13N/A

1119

423

N/A

446

6.18

N/A

6.25

593

N/A

599

596

N/A

N/A

N/A

102

Iner

t (50

% O

2)N/A

N/A

Iner

t1.

3093

N/A

3972

1211

1016

N/A

1024

374

N/A

391

6.12

N/A

6.19

586

N/A

593

589

N/A

N/A

N/A

103

It(

75%

O2)

N/A

N/A

It

130

84N/A

3928

1197

1446

N/A

1451

459

N/A

487

748

N/A

753

717

N/A

721

719

N/A

N/A

N/A

103

Iner

t (75

% O

2)N/ A

N/A

Iner

t1.

3084

N/A

3928

1197

1446

N/A

1451

459

N/A

487

7.48

N/A

7.53

717

N/A

721

719

N/A

N/A

N/A

104

Iner

t (10

0% O

2)N/A

N/A

Iner

t1.

3089

N/A

3953

1205

1614

N/A

1619

496

N/A

520

7.77

N/A

7.83

745

N/A

751

748

N/A

N/A

N/A

105

Iner

t (40

% O

2)N/A

N/A

Iner

t1.

3088

N/A

3915

1193

1036

N/A

1059

490

N/A

949

5.52

N/A

5.63

529

N/A

539

534

931

N/A

N/A

106

Hf-B

4C (4

0% O

2)0.

90.

0929

N/A

1.37

1724

3.1

3922

1195

7635

N/A

9968

N/A

N/A

N/A

29.2

0N/A

24.4

027

97N/A

2338

2568

562

2006

8251

107

Zr-B

4C (4

0% O

2)0.

5311

0.10

75N/A

1.23

9611

8.6

3891

1186

9072

N/A

1245

5N/A

N/A

N/A

31.6

5N/A

29.1

730

32N/A

2795

2913

500

2413

2034

910

8Ti

B4C

(40%

O2)

008

80

6/

2286

938

60/

620

620

/83

88

9/

209

20

/23

620

92

988

038

108

Ti-B

4C (4

0% O

2)0.

4088

0.15

76N/A

1.22

8695

.438

6011

77N/A

6240

6240

N/A

838

859

N/A

20.9

745

21.0

7N/A

2364

2019

2191

488

1703

1785

410

9Hf

(40%

O2)

0.31

05N/A

N/A

1.43

9831

0.5

3872

1180

N/A

5077

5068

N/A

768

784

N/A

17.3

717

.54

N/A

1958

1680

1819

575

1244

4007

110

B4C

(40%

O2)

0.06

37N/A

N/A

1.18

363

.738

2411

66N/A

9868

9817

N/A

1029

1042

N/A

25.9

325

.82

N/A

2923

2474

2698

461

2237

3511

6

77

Figu

re B

.1: (

cont

.)

78

Appendix C:

MATLAB Analysis Code

C.1: Quasi-Static Pressure Curve Analysis

t = tC_beg(:,1);

rel = C_beg(:,1);

% for A

start_A_lin = -1.5;

finish_A_lin = .30;

%Extrapolated Linear Region

start_A_linext=.3001;

finish_A_linext=4;

%%Curved Region

start_A_exp = 50;

%%finish_A_exp = max(tC_beg);

finish_A_exp = max(tC_beg);

%%Extrapolated Curve Region

start_A_exp2 = 0;

finish_A_exp2 = start_A_exp-.0001;

S_A_lin = find(t>start_A_lin & t<finish_A_lin);

S_A_lin2 = find(t>start_A_linext & t<finish_A_linext);

S_A_exp = find(t>start_A_exp & t<finish_A_exp);

S_A_exp2 = find(t>start_A_exp2&t<finish_A_exp2);

%%Curve A%%

A_lin = rel(S_A_lin);

t_A_lin = t(S_A_lin);

t_A_linext=t(S_A_lin2);

A_exp = rel(S_A_exp);

t_A_exp = t(S_A_exp);

t_A_exp2 = t(S_A_exp2);

% Define your exponential function

fh = @(x,p) p(1) + p(2)*exp(-x./p(3))

% define the error function. this is the function to

% minimize: you can also use norm or whatever:

79

errfh = @(p,x,y) sum((y(:)-fh(x(:),p)).^2)

% an initial guess of the exponential parameters

p0 = [mean(A_exp) (max(A_exp)-min(A_exp)) (max(t_A_exp) - min(t_A_exp))/2];

% search for solution

P = fminsearch(errfh,p0,[],t_A_exp,A_exp)

% plot exponental graphs

f1 = fh(t_A_exp,P);

f2 = fh(t_A_exp2,P);

p2=polyfit(t_A_lin,A_lin,1);

f3=polyval(p2,t_A_lin);

f4=polyval(p2,t_A_linext);

%%Determing the Intersection

elements1=length(f2);

elements2=length(f4);

Diff=elements1-elements2;

Diff2=abs(f2(1:elements2)-f4);

Minimum=min(Diff2);

Value=find(Diff2==Minimum);

Curve_Intersect=f2(Value)

Linear_Intersect=f4(Value)

P_mean=(Curve_Intersect+Linear_Intersect)/2

%%determine the time of peak pressure

Peak_Pressure_Time=tA_beg(Value)

% plot the result

plot(t,rel,'g',t_A_exp,A_exp,'bo',t_A_exp,f1,'r-',t_A_exp2,f2,'r',t_A_lin,f3,'bo',t_A_linext,f4,'r')

80

C.2: Impulse Analysis

%%convert data to time scale%%

t = [Tstart*1000:Tinterval*1000:Tstart*1000+(Length-1)*Tinterval*1000]';

%%calculate the mean of the baselines to get a more accurate number%%

A_mean=mean(A(1:1000),1);

B_mean=mean(B(1:1000),1);

C_mean=mean(C(1:1000),1);

%%Convert Gems-15 Data from Voltage to Pressure%%

D=[A-A_mean]/.533333;

%%Convert Gems-45 Data from Voltage to Pressure%%

Z=[B-B_mean]/.266666;

%%Subrtract the base line for sealed gauge Kulite-25SG%%

V=(((C-C_mean)/125)/.1)*25;

%%Set the threshold for the start and end of impulse curves%%

beg_thresh_per = 0.01;

end_thresh_per = 0.01;

%%Determine where the Impulse curve begins%%

A_thresh_beg = A_mean * (1+beg_thresh_per);

B_thresh_beg = B_mean * (1+beg_thresh_per);

C_thresh_beg = C_mean * (1+beg_thresh_per);

A_thresh_end = A_mean * (1+end_thresh_per);

B_thresh_end = B_mean * (1+end_thresh_per);

C_thresh_end = C_mean * (1+end_thresh_per);

% find positions of beginning data all values in A greater than beginning

% threshold

[Pos Val] = find(A(:,1) > A_thresh_beg);

[Pos1 Val1]=find(A(:,1) > A_thresh_end);

[Pos2 Val2] = find(B(:,1) > B_thresh_beg);

[Pos3 Val3]=find(B(:,1) > B_thresh_end);

[Pos4 Val4] = find(C(:,1) > C_thresh_beg);

[Pos5 Val5]=find(C(:,1) > C_thresh_end);

tA_beg = t(Pos,1);

A_beg = D(Pos,1);

tB_beg = t(Pos2,1);

B_beg = Z(Pos2,1);

tC_beg = t(Pos4,1);

C_beg = V(Pos4,1);

81

%%plot(t_beg,B_beg,'k',t_beg,A_beg,'r

Impulse_Gems15=trapz(tA_beg, A_beg)

Impulse_Gems45=trapz(tB_beg, B_beg)

Impulse_Kulite25=trapz(tC_beg, C_beg)

Max_Gems15=max(tA_beg)

Max_Gems45=max(tB_beg)

Max_Kulite25=max(tC_beg)

Impulse15=trapz(t,D);

Impulse45=trapz(t,Z);

ImpulseKulite25=trapz(t,V);

82

C.3: Velocity Analysis

%%convert data to time scale%% t = [Tstart*1000:Tinterval*1000:Tstart*1000+(Length-1)*Tinterval*1000]'; %%calculate the mean of the baselines to get a more accurate number%% A_mean=mean(A(1:100),1); B_mean=mean(B(1:100),1); %%Set the threshold for the start and end of impulse curves%% beg_thresh_per = 0.95; %%Determine where the Impulse curve begins%% A_thresh_beg = A_mean * (beg_thresh_per); B_thresh_beg = B_mean * (beg_thresh_per);

% find positions of beginning data all values in A less than beginning % threshold [Pos Val] = find(A(:,1) < A_thresh_beg); [Pos1 Val1] = find(B(:,1) < B_thresh_beg); t_beg = t(Pos,1); A_beg = A(Pos,1); t_beg2 = t(Pos1,1); B_beg = B(Pos1,1); Diode1=t_beg(1,1); Diode2=t_beg2(1,1); Time=Diode2-Diode1 Velocity_FS=.24666666/Time*1000 Velocity_MS=.075184/Time*1000 %%2.97 in is .2475 ft & .075438 m%% %%2.87 in is .23916666 ft & .072898 m %% %%2.89 in is .24083333 ft & .073406 m%% %%2.96 in is .24666666 ft & .075184m %%

83  

Appendix D: Endevco 106/109 Settings

Figure D.1: Endevco 106/109 settings (top channel only)

Figure D.2: Gain calculations for Endevco 106/109

Gain1

FS mv( )

100

%Setting 10000

84

Appendix E:

SOP for Model 700 Remington Rifle

Standard Operating Procedure for safe experimentation with the Model 700 Remington Rifle

1. Put the safety mechanism in the “S” position.

2. Ensure that the AV-DC volt transformer is unplugged and in the off position.

3. Ensure the firearm is pointed in a safe and intended direction.

4. Ensure that the chamber is secure and assembled.

5. Place the device spacer on the table between the locker and the chamber.

6. Place the bolt in the weapon (if not already done so).

7. Place one cartridge on the magazine follower or in the chamber.

8. Slide the bolt handle forward, then push the bolt handle down to lock the cartridge into the

chamber.

9. Without placing your fingers in the bullet path perform a check for proper alignment with the

muzzle laser pointer as the weapon may have shifted during loading.

10. REMOVE the LASER POINTER

11. Adjust the solenoid bar so that it is as far front of the trigger guard as possible.

12. Set any hallway notification signs in place.

13. Put the safety mechanism in the “F” position.

14. Assume a safe position behind the adjacent room wall.

15. Insert proper hearing protection.

16. Plug in the power inverter.

17. Fire the weapon.

18. Turn off solenoid & unplug the transformer.

19. Place the weapon on “S”

20. Inspect lab results.

In case of a misfire

1. Turn off solenoid & unplug the transformer.

2. Place the weapon on “S”

3. Remove the bolt and unused round.

4. Inspect the round.

5. Begin at step #6 from above.

85

Appendix F:

Data Recording Sheet Date______________________ Time______________________ Test#_____________________ System____________________ Specimen__________________

Gun Powder Type_____________________________ Gun Powder Weight__________________________ Empty Bullet Weight_________________________ Filled Bullet Weight___________________________ Specimen Weight_____________________________ Total Bullet Weight (w/sealant)_________________ Chamber Pressure:

Location on Chamber:

Ch A Ch B Ch C

Sensor Type:

Gain Setting:

Trigger Setting:

Voltage:

Voltage Sensitivity:

Time Scale:

Bullet Velocity Settings:

Position: Ch A Ch B

Diode Type:

Trigger:

Voltage:

Voltage Sensitivity:

Time Scale:

Misc

86

Appendix G:

Proposed Bullet Press Design Sketches

Figure G.1: Sketches depicting a proposed “mass production” bullet powder press

87

Appendix H:

Remote Trigger Drawings

Figure H.1: Remote trigger dimensions

88

Figure H.2: Remote trigger CAD model

89

Appendix I:

Mounting Block Sketch

Figure I.1: Mounting block sketch

90

Appendix J:

Reactive Material Moisture Study

Table J.1: Moisture absorption from the storage of vacuum dried reactive materials in ambient air for 15 days

91

Appendix K:

Experimental Results in Energy Output per

Volume

Figure K.1: Energy output per volume for CuO systems

92

Figure K.2: Energy output per volume for W-Zn-Zr systems

Figure K.3: Energy output per volume for W-Zn-Hf systems

93

Figure K.4: Energy output per volume for KClO4 systems

Figure K.5: Energy output per volume for B4C systems

94

Figure K.6: Energy output per volume for B4C systems in 100% nitrogen

Figure K.7: Energy output per volume for Bi2O3 systems in air

95

Appendix L:

XRD Analysis Results

Figure L.1: Residue from inert test in 100% nitrogen (Test#92)

96

Figure L.2: Mixture of Al-CuO before testing

Figure L.3: XRD results for the Al-CuO system (Test #33)

97

Figure L.4: Mixture of W-Zn-Zr 5/16/79% before testing

Figure L.5: W-Zn-Zr 5/16/79% residue sample (Test#35)

98

Figure L.6: Mixture of W-Zr (33/66%) before testing

Figure L.7: Residue from W-Zr (60/40%) test in air (Test#61)

99

Figure L.8: Mixture of Hf-KClO4 before testing

Figure L.9: Residue from B4C test in 100% nitrogen (Test#95)

100

Figure L.10: Mixture of Ti-B4C before testing

Figure L11: Residue from Ti-B4C test in 100% nitrogen (Test#98)

101

Figure L.12: Mixture of Hf-Bi2O3 before testing