SANDEEP LAL

LABASA CAMPUS

TE 155: ASSIGNMENT 2

ENGINEERING MATERIALSA material either in solid form or other condensed phases are

defined as any substance that is projected for use for definite

application. Materials can be found all around us that are from

earth’s crust or in anything from building to spacecraft.

Crystalline and Non- Crystalline are to categories that can be

used to classify the materials. Metals, ceramics and polymers are

some examples of traditional materials and on the other hand semi

conductors, nano-materials and bio- materials are some examples of

advanced materials. In the earth’s crust, iron is the most common

element and nearly every construction undertaken there is at least

a little use of iron. Iron is considered as a chemical element and

in the periodic table it can be located with a symbol Fe with an

atomic number 26. Iron ore through several processes can be

converted into various types of iron and on of this is steel. The

other type of material that had been used over centuries is

ceramic. Ceramic is derived from common, naturally raw materials

such as clay and quartz sand. Some of the products made from

ceramics that are familiar to us are china tableware, clay brick

and tiles, clay pots and porcelain flower vases. In this

assignment, I will look into how two such materials, steel and

porcelain, are manufactured, the raw materials used, their

properties, sustainability and its application.

Firstly, the raw materials used to manufacture these materials

are as follows: Steel, the raw materials used are iron ore, coal,

limestone and recycled steel.

The primary components used for porcelain are clay, feldspar or

flint and silica

These are the raw materials that are blended together to

manufacture the materials such as steel and porcelain.

Secondly, will know look at how these various raw materials are

processed to create the useful materials, in the other words the

manufacturing process. Now looking into how steel is manufactured:

The iron ore are crushed and sorted so that only the best grades

of iron ore are introduced in the blast furnace (tower shaped

structure with its interior is made of steel and fitted with heat

resistant bricks) together with limestone and coke. A very hot air

is blown through the use of nozzle situated at the bottom of the

furnace. There is formation of carbon monoxide in the furnace as

the coke burns in the presence of hot air reacting with oxygen.

Reaction of iron ore and carbon monoxide results in formation of

carbon dioxide and pure iron.

Picture of a Blast Furnace

The following chemical reactions take place in the blast furnace

that enables the formation of carbon dioxide and pure iron.

The molten iron from the blast furnace is than poured into an

upright cylindrical vessel, shown in the picture below (figure 1).

Pressurized oxygen gas is introduced on top of the molten metal.

The impurities present in the iron such as manganese, phosphorus,

silicon and excess carbon reacts with the oxygen and forms slag

After this process, the molten steel settles below in the vessel

and the slag floats on top of the vessel. The vessel is rotated

horizontally so that the molten steel can be tapped off (as

illustrated in Figure 2). The molten steel is than processed

through continuous casting processes by machines to produce

stainless steel slabs (as shown in figure 3 & 4). These slabs go

through a surface grinding process so that all the uneven surface

and defects are removed.

Figure 1: Cylindrical Vessel

Temperature

Reaction

At 500 °C

3Fe2O3 +CO → 2Fe3O4 + CO2

Fe2O3 +CO → 2FeO + CO2

At 850 °C

Fe3O4 +CO → 3FeO + CO

At 1000 °C

FeO +CO → Fe + CO2

At 1300 °C

CO2 + C → 2CO (formation of carbon monoxide)

At 1900 °C

C+ O2 → CO2 ( production of carbon

dioxide)

FeO +C → Fe + CO (iron and carbon dioxide is produced)

Figure 3: Hot Working Figure 4: Cold Working

Figure 2: Steelmaking Process

Thirdly, porcelain is another material that is widely used in the

engineering material. Manufacturing of porcelain, the raw

materials such as clay, feldspar and silica are carried out as

follows:

A. Crushing

Reduction of raw material to desired size is achieved by

using jaw crushers (using swinging metal jaws). Than it is

further reduced in size by use of hammer mills (steel –tired

wheels, rapidly moving steel hammers). To achieve very fine

particles, ball mills filled with spherical shaped steel or

ceramic grinding media are used.

B. Cleaning and Mixing

The ingredients after the breakdown, passes through a series

of screens so that undesired sized materials are removed. It

is then mixed with water, for this produces the preferred

texture. A magnetic filtration is carried out to remove the

iron from the slurries.

C. Forming Body

The porcelain body is formed by either of the methods:

Soft plastic forming – manual molding of clay shapes is

by the use of wheel throwing. The desired amount of clay

is placed on the wheel and shaped as the wheel spins.

Jaw

crushersHammer Ball mills Grinding

Stiff plastic forming – use of a steel die through which

the body is forced that enables to form a column of

uniform girth.

Pressing – this method compacts and shape dry bodies in

rigid die or flexible mold.

Slip Casting – slurry is poured into a porous mold of

the desired shape.

D. Bisque-firing – after the shape is formed, the porcelain

parts are exposed to a low temperature to vaporize volatile

contaminants and also minimize shrinkage.

E. Glazing – proper coating is applied to the porcelain ware by

means of painting, pouring, dipping or spraying.

F. Firing – a kiln or oven is used to heat the porcelain ware so

that it is hardened and produces irreversible changes in the

product made.

After the completion of all this manufacturing process than only

the final product is achieved that is of high quality and

marketable.

In addition, the material poses certain property that enables it

to perform well in the required engineering application. The

properties are tabulated as follows:

STEELPhysical Mechanical Unique PropertiesStrength Toughness High Impact Strength Stain resistant Ductility Resistance to abrasionNon conductive Durability Self ProtectiveHygienic Weld ability Simple to use High Tensile StrengthMalleability High Modulus of

Elasticity

PORCELAIN

Physical Mechanical Unique PropertiesSpecific gravity Hardness Color PerformanceThermal conductivity Abrasion and Wear

ResistanceColor Availability

Flexural Strength Lubricity Gloss Compressive Strength Adhesion Light ReflectanceMaximum Operating Temperature

Impact Resistance Texture

Tensile Strength Flexibility Clean ability Thermal Expansion

Furthermore, the sustainability of the material is also important

that is the recyclability, energy to produce the product, impact

on human and environment. Therefore, looking at steel it is not

harmful to people, low maintenance cost, long life due to high

corrosion resistance, uses fewer resources to manufacture and can

be easily recycled ( the scrap that is not recycled, turns into

iron oxide and returns to the ground so it can be said that steel

is sustainable. On the other hand, porcelain is also sustainable

because it is eco-friendly; material extraction is cheap because

the raw materials are close to the proximity; it does not emit or

absorb pollutants and it can be recycled easily by mixing it with

water and the waste can be used for production process.

Lastly, the application of the two types of material; steel and

porcelain. The application of the material is tabulated as

follows:

STEEL APPLICATION CAN BE CLASSIFIED INTO FIVE GROUPS:a. Transportb. Construction c. Energy d. Packaging e. Appliances and Industry

PORCELAIN IS MOSTLY USED FOR:a. Utilitarian Waresb. Artistic Objectsc. House Waresd. Decorative Itemse. Laboratory Equipmentf. Kitchen and Bathroom Wareg. Electrical Insulating Materialh. Building Material- tiles and panels

In conclusion, engineering materials are very important towards

the growth of the advancing era of technology. Most of the raw

materials to process and manufacture these materials are naturally

available and are carefully selected for the desired application.

It could be seen that the raw materials undergo several processing

stages before it is ready to be molded into final products such as

crushing, heating, casting, molding, various bonding stages and

polishing. The materials have physical, mechanical, chemical and

electrical properties that make it unique for its desired use.

Apart from these, the materials should be sustainable in regards

to environment, humans, energy produced and recyclability. The

materials should also be applicable to various uses such as

industrial, construction, electrical and transport.

BIBLIOGRAPHY

Advanced Engineering Materials - Wiley Online Library

http://onlinelibrary.wiley.com/doi/10.1002/(ISSN)1527-2648/home

Materials Science and Engineering : A - ScienceDirect.com

http://www.sciencedirect.com/science/journal/09215093

The Manufacture of Steel

http://nzic.org.nz/ChemProcesses/metals/8A.pd

Manufacturing Process for Iron and Steel

http://www.jfe-21st-cf.or.jp/chapter_2/2a_1.html

How porcelain is made - material, making, used, processing

http://www.madehow.com/Volume-1/Porcelain.htm

Chapter 6. Mechanical Properties of Metals

http://www.virginia.edu/bohr/mse209/chapter6.htm

MARKING CRITERIA FOR THIS ASSIGNMENT 2

Name: ________________________ I.D No. ____________________________

 

  PART A Excellent(4) Proficient(3) Average(2) Poor(1)  A Coverage of

terms of reference

All terms of reference met with detailed   appropriate analysis

All terms of reference met

Most terms of reference met

Few terms of reference met

 

B Introduction Introduction   clearly establish context

Introduction   clearly establish some context

Introduction   attempts to establish context

Introductionfails to establish context

 

C Materials and Methods:

Precisely and   clearly outlined the method; reported the detailed proceduresof the study;   specified the use of the two materials in details

Clearly outlined   the method; reported the procedures of the study but a few points were not   detailed enough; mentioned most of the two materials

Briefly outlined   the method; brieflydescribed the procedures; only mentioned one material

Briefly outlined   the method; procedures ofthe study were described ambiguously

 

D Content:   

All content   directly related tothe topic.

Content directly   related to the topic.

Demonstrated   Basic understanding of the topic

Few facts   related to the topic.

 

E Visuals Visuals were clear,simple, accurate, titled & sourceslabelled

Visuals were   simple and clear but some labels & sources were missed

Visuals were not   labelled and sources in details

No Visuals  

F Background: Provided a very   comprehensive and detailed background; a wide and deep coverage of the topic

Showed a   detailedbackground but not comprehensive enough; sufficiently covered the   work but a few areas notdeep enough

A background   with basic information; some key pointsmissed; coveredthe topic at ageneral level

Lacked of   significant details in the topic

 

G Organisation Well organised Thoughtfully   Somewhat   Irregular and  

Total score: …….../40……   15% = …………      Markers Initial: ………….