Important of engg materials

ENRL NO:130110119056 - VINAY SUDANI130110119057 - PAVAN SUREJA130110119058 - MANSI SUTARIA130110119059 - PARTH VASAVA130110119060 - DEEP VASHI

Important Engineering Materials

CLASSIFICATION OF ENGINEERING MATERIALS

Engineering

materials

Metals & their alloys

Ferrous metals

Non-ferrous metals

Non -metals

CONTI...

Metals and their alloys : such as iron,steel,aluminium,copper,nickel,etc.

The ferrous metals : are those which have iron as their main constitutent.

Such as iron,steel &cast iron.The non-ferrous metals : are those which has a

metal other than iron as their main constituent. Such as alluminium,copper,tin,zinc,etc.Non-metals : such as

ceramics,glass,plastic,rubber etc.

PROPERTIES OF MATERIALS

DEFINATION……………………

IT IS DEFINED AS A QUALITATIVE OR QUANTITATIVE MEASURE OF RESPONSE OF MATERIAL TO EXTERNALLY IMPOSEDCONDITIONS LIKE FORCE AND TEMPERATURE.

TYPES………

PHYSICAL MECHANICAL CHEMICAL THERMAL ELECTRICAL MEGMETIC OPTICAL TECHNOLOGICAL

1. STRENGTH :- ABILITY TO RESIST THE BREAKING

UNDER THE ACTION OF EXTERNAL LOADS.

2. STIFFNESS :- ABILITY TO RESIST DEFORMATION

UNDER STRESS.3. HARDNESS:- ABILITY TO RESIST SCRATCHING ,

WEAR ,PENETRATION ,ABRASION ,ETC.

4. DUCTILITY:- PROPERTY TO UNDERGO DEFORMATION

UNDER TENSION WITHOUT BREAKING .5. BRITTLENESS:- PROPERTY OF MATERIAL BY VIRTUE OF

WHICH IT WILL FRACTURE WITHOUT APPRECIABLE DEFORMATION.

6. TOUGHNESS:- PROPERTY TO RESIST FRACTURE DUE TO

HIGH IMPACT LOADS LIKE HAMMER BLOWS AND ABSORB A CERTAIN AMOUNT OF ENERGY.

7. MALLEABILITY:- ABILITY TO WITHSTAND DEFORMATION

UNDER COMPRESSION WITHOUT FRACTURE.

8. ELASTICITY:- ABILITY TO REGAIN ITS ORIGINAL SHAPE

AFTER DEFORMATION WHEN EXTERNAL LOADS ARE REMOVED.

9. PLASTICITY:- ABILITY TO BE PERMANANTLY DEFORMED

WITHOUT FRACTURE EVEN AFTER THE REMOVAL OF THE LOAD.

10. RESILIENCE:- ABILITY TO ABSORB OR STORE ENERGY

AND TO RESIST SHOCK AND IMPACT LOADS.

11. CREEP:- SLOW AND PERMANENT DEFORMATION

DUE TO CONSTANT STRESS AT HIGH TEMPERATURE FOR LONG TIME IS CALLED CREEP.

12. FATIGUE:- WHEN MATERIAL FAILS AT STRESSES

BELOW YIELD POINT STRESSES SUBJECTED TO REAPETED TENSILE AND COMPRESSIVE STRESSES .THIS FALURE IS CALLED ‘FATIGUE’.

13. CORROSION RESISTANCE:- PROPERTY OF MATERIAL WHICH RESIST

CORROSION.

14. THERMAL CONDUCTIVITY:- ABILITY TO CONDUCT THE AMOUNT OF

HEAT PER UNIT TIME THROUGH A UNIT AREA .

15. ELECTRICAL RESISTIVITY:- PROPERTY DUE TO WHICH IT RESIST THE

FLOW OF ELECTRICITY THROUGH IT.16. ELECTRICAL CONDUCTIVITY:- PROPERTY DUE TO WHICH IT ALLOWS

THE FLOW OF ELECTRICITY THROUGH IT.

17. CASTABILITY:- THE EASE WITH WHICH THE MATERIAL

CAN BE GIVEN VARIOUS SOLID SHAPE FROM LIQUID STATE .

18. WELDABILITY:- ABILITY TO BE WELDED UNDER THE

FABRICATION CONDITION.

19. MACHINABILITY:- THE EASE WITH WHICH MATERIAL CAN

BE CUT OR REMOVED BY CUTTING TOOL WITH SURFACE FINISH .

20. WORKABILITY:- THE EASE WITH WHICH METAL CAN

CHANGE ITS SHAPE IN SOLID STATE.

FERROUS MATERIALS• Materials consisting primarily of IRON as its main component

are called FERROUS materials.• They are widely used as they provide wide range of

properties.• Principle ferrous metals:• 1)Wrought Iron• 2)steels• 3)alloy steels• 4)cast iron• Raw material used :- pig iron(obtained by smelting of

iron in blast furnace)

Name Properties UsesLow Carbon Steel (Mild Steel)(Carbon 0.1%-0.3%)(iron + carbon)

•Fairly Strong•Rusts easily

girders, car body panels, nuts and bolts, Food cans, car body panels

Medium Carbon Steels(Carbon 0.3%-0.7%)(iron + carbon)

•Harder than low carbon steel

Nails and screws, metal chains, wire ropes, screwdriver blades, engine parts, bicycle wheel rims

High Carbon Steel (tool steel)(Carbon 0.7%-1.3%)(iron + carbon)

•Harder than medium carbon steel•Brittle

Chisels, hammers, drills, files, lathe tools, taps and dies.

High Speed Steel(Carbon 0.6%)(iron + carbon + tungsten + chromium)

•Harder and more lasting than high carbon steel•Can retain its hardness at high temperature (700°C)

Cutting tools for lathes and drill bits

FERROUS METAL

FERROUS METALName Properties UsesStainless Steel(Carbon 0.2%)(iron + carbon + nickel + chromium)

•Hard and tough•Polishes well•Resistant to corrosion and rust

Cutlery, kitchen utensils and appliances, sinks, surgical instruments

Cast Iron(Carbon 2%-4%)(iron + carbon)

•Hard and brittle•Rusts easily

Car engine blocksManhole coversEngineer’s vice

Wrought Iron

• Highly refined iron(almost 99% iron).

• Properties :- the slag fibres improve strength & corrosion resistance of iron

• Tough, malleable & ductile

• Applications :- bolts, chains, railway couplings.

Steels

• Alloy of carbon and iron.• Carbon range :- 0.5-1.5%• Classified on basis of carbon content:-• 1)low carbon steel- (0.15-0.30%)• 2)medium carbon steel- (0.30-0.60%)• 3)high carbon steel – (0.60-1.50%)

• Hardness and strength varies with carbon content.

FERROUS METAL

High

Harder

Ferrous MetalsLOW CARBON STEEL

Ferrous MetalsMEDIUM CARBON STEEL

Ferrous MetalsHIGH CARBON STEEL

Alloy steel

• Elements other than carbon are added in sufficient amounts to achieve desired properties.

• Main types are:-• 1)stainless steel• 2)heat resisting steel• 3)high speed steel• 4)spring steel

• Stainless steel- contains chromium, nickel, molybdenum, and manganese((utensils, surgical instruments, dairy industries))

• Heat resisting steels- tungsten, chromium & nickel ((gas turbines, furnace parts))

• High speed steels- main component-tungsten, chromium & vanadium ((high speed cutting tools)).

• Spring steels- contains manganese & silicon ((leaf and helical springs))

Ferrous MetalsHIGH SPEED STEEL

Cast Iron

• Alloy of carbon & iron(carbon – 2-4.3%)• Very brittle % less ductile.• Various type are:-• 1)Grey cast iron• 2)White cast iron • 3)Malleable cast iron

Ferrous MetalsCAST IRON

• Grey cast iron- contains carbon as GRAPHITE FLAKES (automotive cylinder blocks, fly-wheels, pipe fittings)

• White cast iron- contains carbon as cementite(iron carbide)

• Extremely hard & brittle(mill liners, grinding balls)

• Malleable cast iron- formed by long heat treatment to white cast iron.

• Ductile - Can be bent without breaking- high tensile strength (agricultural machinery, door hinges)

NON FERROUS MATERIALS

Non-ferrous materials are those that contain a metal other than Iron as its chief constituent.

CHARACTERISTICS:1. Ease of manufacturing2. Corrosion resistant3. Electrical and thermal conductivity4. Weight

ALUMINIUM AND ITS ALLOYS

Benefits: Lighter than steel, copper Highly corrosion resistant Good Machinability, Formability, Castability Silvery white colour

Drawbacks: Low hardness, poor strength

Examples: Duralumin, Y-alloy Applications: Aircraft, automobile industry,

overhead cables, wiring, cooking utensils

Y-Alloy Duralumin

COPPER AND ITS ALLOYS

Benefits: soft Ductile Malleable Good conductor of electricity Higher resistance to corrosion

Examples: Brass, Bronze Applications:1. Brass (Cu+Zn): used in hydraulic fittings, pipe

linings, utensils, bearings, etc.2. Bronze(Cu+Sn): used in pipe linings, bushes,

gears, springs, utensils etc.

BronzeBrass

LEAD AND ITS ALLOYS

Benefits: Heaviest and softest Malleable and ductile Can be rolled easily Good corrosion resistance Good lubricating properties High radiation absorbing power

Applications: used for making solders, as a lining for acid tanks, water pipes, bearing, batteries etc.

LEAD BLOCKS

TIN AND ITS ALLOYS

Benefits: Brightly shining white Malleable and soft Can be rolled easily into sheets

Applications: used for making solders, as a protective coating on iron and steel, for making tin foil used as moisture proof packing, etc.

TIN LUMP

NICKEL AND ITS ALLOYS

Benefits:‾ High mechanical strength properties‾ Corrosion resistance Applications: used for production of stainless

steel, propellers, condenser tubes etc.

Monel metal Nitinol stench

NON – METALLIC MATERIALS

Why we use non – metallic material?These type of materials are used in engineering due to –

Low costLow densityResistant to heatResistant to electricityFlexibility

Non-metallic

natural

synthetic

Natural material : rubber,wood,ceramics,asbestos

Synthetic materials : plastics,polymers,etc.

LETS DISCUSS BRIEFLY ABOUT SOME OF IMPORTANT NON-METALLIC MATERIAL :

TIMBER

It is the wood which made suitable for engineering practice.

Wood is natural polymer composite.The principle polymeric molecules are those

of cellulose.Is obtained by cutting trees after their full

growth.

STRCTURE OF TIMBER

The innermost part or core is known as pith.Heart wood which consists of innermost

annular rings is around the pith.The thin layer below the bark is called the

cambium layer.The thin fibers,which extend from pitch

outwards and hold the annular rings together are called medullar rays.

The heart wood and sap wood from the main part of timer for suitable application.

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Applications:• It is widely used for making door-window,

roof members, furniture, sound-proof construction, tool-handles, railway sleepers, sports goods, packing cases, etc.

Advantages:• It has high strength to weight ratio.• Easily desired shape can be given.• Attractive appearances and good toughness.

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Disadvantages:• Properties of timber are being changed with

season.• It is inflammable and strength is very along

the length and across the length.

ABRASIVE MATERIAL

Abrasive material is hard material.It is used in the form of powder, emery-paper,

emery-cloth, solid discs, wheels or bars of various shapes and sizes.

E.g., Silicon carbide, aluminium oxide, emery, diamond, etc. Are the various abrasive materials.

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Application:• Wear away softer material.• Grinding• Cutting• Scratching• Rubbing• Polishing

SILICA

SiO2 is basically a refractory material which can withstand high temperatures.

Most simple silicon material found on earth.The tetrahedron structure of silica is

electrically neutral.It has three primary polymorphic crystalline

forms which are known as –1. Quarts2. Cristobalite3. tradymate

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Application:

Blast furnaces Chemical reactor liningLining of aluminium melting furnacesRotary kilns

CERAMICS

Ceramics materials are defined as those consisting of compounds of metallic and non-metallic elements.

The compounds are usually oxides, nitrides, carbides, etc.

The very commonly used ceramic materials include clay, cement and glass.

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Properties:

1. Greater stability at high temperatures. 2. Very hard 3. Strong4. Dense materials5. Brittle6. Less ductile7. They are chemically inert so they are not

affected by chemical actions and remain stable under severe environmental conditions.

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Applications:

In the field of heat engines.Electronic packaging.Gas turbine.Chemical rector lining.Electrical Resistance heating elements.

GLASS

Glass is a transparent silica product which may be amorphous or crystalline , depending on heat treatment.

It refers to material which is made by the fusion of mixture of silica, basic oxides and a few other compounds that react either with silica or with the basic oxides.

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Properties :

Non-corrosive in natureHigh temperature resistanceBetter optical propertiesChemical stability

It is used for glass equipments for various use.

GRAPHITE

Graphite is an allotrope of carbon.

Properties :Conductor of electricityVery stable materialWithstand high temperatures.

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Application:

As electrodes of an arc lamp and arc welding.In bronze as a lubricant.For making graphite crucibles in- 1. steel making,2. brake lining,3.foundry facings,4.zinc-carbon batteries,5.Electric motor/generator brushes 6.Pencils for drawing and writing.

DIAMOND

It is an allotrope of carbon.The hardest known material.They are naturally available material.Artificial diamonds are also available.

they are manufactured by high pressure , high temperature process.it is yellow in colour due to nitrogen as impurity.

diamond is the hardest and tough and has the characteristics of high dispersion of light due to which it is used in many industrial application and jewelry.

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They make superlative abrasive due to this it is used in engraving tools.

Diamonds are widely used in drilling and other finishing operation like lapping , honing and super finishing .

PLASTICS

The plastics are synthetic materials which are moulded into shape under pressure with or without the application of heat.

These can also be cast,rolled,extruded,liminated and machined.

Plastics are usually divided into two groups , thermoplastics and thermosetting plastics.

Plastic have been increasingly accepted as engineering material.

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Properties :Attractive materialLow weightLow costNo moistureChemical resistanceToughnessAbrasive resistance StrengthAppearance InsulationFormabilitymachinability

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Application :In the manufacture of aeroplaneAutomobile partsMaking safety glassesLaminated glassesSelf-lubricating besrings.

POLYMER

The basic structural units of polymers are referred to as monomers.

A polymers is therefore , made up of thousands to form a large molecule of colloidal dimension , called macromolecules.

The process by which polymers are formed is a chemical reaction known as polymerization.

There may be naturally occurring polymers or synthetic polymers.

Polyethylene ,polytyrene, nylon ,terelene,dacron,etc. are the synthetic polymers.

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Low density , good corrosion resistance , excellent surface finish , good insulator etc. are some of the characteristics of polymer.

Applications:Polymers are used for making high structure

fibers like silk and wool.They are also used in optical industries ,

reflectors , packaging and coating material etc.

COMPOSITE MATERIALS

A composite material is defined as a combination of more than one materials which are used in combination to rectify a weakness is one material by a strength in another.

This combination of two or more materials offers properties distinctly different from those of the individual materials used to make the composite.

Composites may be man-made or natural.Wood material obtained from tress is also a

composite which is formed naturally.Wood consists of strong and flexible cellulose fibers

surrounded by a stiff material called lignin.