engineering alloys(non ferrous)

8/10/2019 Engineering Alloys(Non Ferrous)

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Engineering AlloysNon - Ferrous


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COPPER AND ITS ALLOYS

ALUMINUM AND ITS ALLOYS

TITANIUM AND ITS ALLOYS

NON FEROUS MATERIALS


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COPPER

BRASSES (Cu- Zn ALLOY)

BRONZES

COPPER- NICKEL ALLOYS

COPPER AND ITS ALLOYS


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PROPERTIES OF COPPER

High electrical conductivity (best amongconductors)

It has good ductility and malleabilitybecause of its FCC structure

COPPER


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Good corrosion resistance to general

atmospheric conditions

Good thermal conductivity

Good machinability and ease of

fabrication

COPPER


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APPLICATIONS

Used for making electricalconductors(99.9% purity)

Automobile radiators and inrefrigerators for circulating fluids.

COPPER


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Used in distillery and in other process

equipments (due to its good corrosion

resistance and non-toxic nature of

copper ions)

The free cutting copper ( 0.6% tellurium

copper), which has excellent

machinability, is used for bolts, welding

tips, switch gears, relays, etc.

COPPER

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BRASSES

Brasses are the alloys of Copper andZinc.

Equilibrium diagram of Cu-Zn

-Brasses

+ Brasses


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BRASSES

Cu-Zn Equilibrium diagram and mechanical properties

10 20 30 40 50 %Zn

910C

'

L

+L +L

+

+'

+450C


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The equilibrium solubility of Zn in Cu is

around 38% ( i.e, the phase or FCC

structure) and is sharply influenced bycooling rate.

Under industrial cooling rates, the

solubility reduces to 30%.

BRASSES


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As the Znaddition exceeds the solubility

limit a second phase (BCC)is formed.

And around 450C the phase

undergoes a order-disorder

transformation and below 450 C it

forms ordered structure of ( i.e, '

phase)

BRASSES


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The tensile strength and ductility of

brass increases with increasing amount

of Znupto 30%( i.e, the solubility limit)

With the appearance of the phase (ie,

>30%) the strength continues to

increase but the ductility begins to

decrease.

BRASSES


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Therefore, most commercial alloys

contains less than 40%Zn.

Upto 20%the colour of brass is red andbeyond 20%it becomes yellow.

BRASSES

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TYPES, PROPERTIES & APPLICATIONS

These are the alloys contain less than

30%Zn.

They are soft, ductile, malleable and

have fairly good corrosion resistance in

annealed condition and are suitable for

cold rolling, wire drawing, etc.

-BRASSES


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Gliding metal (5%Zn) used for making

coins, medals, bullet envelops,

condenser tubes, etc.

Cartridge brass

( 30%Zn) has maximum

ductility and malleability among all the

-brasses.

-BRASSES


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Cartridge brass is also called 70-30brass.

Formed by deep drawing, stretchingand press work operations.

Used for making cartridge cases,radiator fins, rivets and springs.

-BRASSES

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These are the 30 - 40%Zn alloy whichcontains two ( + )phases.

They are hard and strong andfabricated by hot working process

(above 600C) .

Corrosion resistance of these alloys are

less compared to - Brasses.

+ BRASSES


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Muntz metal ( 40%Zn) is used for

utensils, nuts, bolts, pump parts,

condenser tubes, and similar

applications where corrosion resistance

is not severe.

Naval brass

or Tobin brass( 60Cu/ 39Zn/

1Sn) has good corrosion resistance

towards marine environments.

+ BRASSES


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The addition of tin increases the

corrosion resistance towards marine

environment inNaval brass.

It is used for marine hardware,propeller shafts, piston rods, welding

rods, etc.

+ BRASSES

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Bronze is the alloy of copper containing

elements other than zinc ( i.e, Sn, Al, Be,

etc.)

Originally the name bronze was used todenote Copper- Tinalloy.

BRONZES


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Bell metals

(20-25%Sn) used for making

bells are very hard and brittle and giveringing sound.

Gun metal

(88Cu/10Sn/2Zn)used for gunbarrels and ordinance parts,gears,

bearings, etc (Here Znacts as deoxidiser

and improves fluidity of melt)

BRONZES


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Statuary bronze (86Cu/10Sn/2Zn/2Pb)used

for making statues( Here Pb gives a

brownish black colour called patina to

statues)

Wrought phosphor bronze ( 2.5-8% Sn and

0.1-0.35%P) are used for making springs

and electrical contacts.

BRONZES


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Commercial aluminum bronze

orimitation gold

(4-11%Al)are lustrous and their colour

is the finest of all the copper alloys.

The imitation gold is used in jewellery,

heat exchangers, chemical plants, etc.

BRONZES

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Copper and Nickel are completely

soluble with each other both in solid and

liquid states and hence form a

continuous series of solid solutions.

All the alloys are ductile and malleable

and can be worked in both hot and cold

conditions.

Cu Ni ALLOYS


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The corrosion resistance of the alloyincreases as the Ni content increases.

Tensile, proof and fatigue strengthsincreases with the Nicontent, and reaches a

maximum between 60 - 70%Ni.

The alloy becomes progressively white and

beyond 20%Ni it becomes practically

white.

Cu Ni ALLOYS


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Constantan (45%Ni) has a very high

electrical resistivity and a extremely low

(i.e nearly zero)temperature coefficient

of resistance over a temperature range

of 20- 350C.

Constantan

is used for resistors and in

thermocouples.

Cu Ni ALLOYS


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German silver

(5-30%Ni, 5-40%Zn)alloys

have silver-blue white colour and good

resistance to the action of food

chemicals, water and atmosphere and

are used for rivets, screws, costume

jewellery, name plates, etc.

Cu Ni ALLOYS

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ALUMINUM

ALUMINUM COPPER ALLOYS

ALUMINUM SILICON ALLOYS

Y-ALLOY

CORROSION RESISTRANCE OF Al & ITS ALLOYS

ALUMINUM AND ITS ALLOYS


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PROPERTIES OF ALUMINUM

It has FCC structure, good

machinability and workability.

Low density (1/3of steel or Cu alloys)

Good electrical conductivity (about 60%

of Cu, but for equal weight the

conductivity is 200%of Cu)

ALUMINUM


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High thermal conductivity.

Excellent corrosion resistance andoxidation resistance due to the

formation of Al2O3 film on the metal

surface.

Excellent ability of getting alloyed with

other elements like Cu, Si, Mg, Zn, etc.

ALUMINUM


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APPLICATIONS

It has applications where good

formability or very good resistance tocorrosion or both are required and high

strength is not required.

Used in food packing due to the non-

toxic nature of Al2O3.

ALUMINUM


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Due to very low ductile to brittle

transition temperature (i.e, - 40C),

finds application in refrigeration.

It is a powerful grain refiner and is used

in Copper and Brasses to reduce their

cast grain sizes, thereby to increase

mechanical properties with improved

surface finish at lower cost.

ALUMINUM


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Used in the de-oxidation of steel in

manufacturing of killed steels.

Used in making permanent magnets,

shape memory alloys and space alloys.

Used as electrical conductors, cooking

utensils, transportation industry, etc.

ALUMINUM

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The Al-Cu alloys are heat treatable

alloys.

Max solubility of Copper in aluminum is5.65% (at 550C) and


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Duralumin (4%Cu) is used for making

rivets for aircrafts.

Has high specific strength (200MPa)(for

high strength steels 170MPa).

It is a natural ageing alloy and is stored

in refrigerators.

ALUMINUM-COPPER ALLOYS

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The Al-Si alloys are used in castings due to

excellent fluidity.

Higher the silicon content, better the

mechanical properties, corrosion and

oxidation resistance and lower the coefficientof thermal expansion with improved fluidity

and casting characteristic.

ALUMINUM-SILICON ALLOYS


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However, with increase in silicon

content the amount of eutectic increases

which reduces the mechanical

properties.

For hypereutectic compositions, the

presence of primary silicon further

reduces the mechanical properties.



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1.65

4 8 12 16

Temperature

%Si

Al Si Phase diagram

577C


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The eutectic composition is increasedand the eutectic temperature is reduced

by adding small amount of modifying

agents such as metallic sodium to themelt prior to pouring.

Therefore, the alloys upto 16%Si getssolidified as eutectic or hypoeutectic

without the presence of primary silicon.



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The 12% Si alloy has excellent fluidity

and shows less shrinkage during

solidification.

They are used for casting intricate

shapes in automobile industries such as

water cooled jackets, motor housing, etc.

and for pump parts in chemical

industries.


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The composition of this alloy is 4%Cu,2%Ni and 1.5%Mg and the rest is

aluminum.

It has excellent high temperature

strength with fairly good corrosion

resistance and can be easily cast.

It is used for piston and cylinder heads

of diesel and heavy duty petrol engine.

Y - ALLOY

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The high corrosion resistance is due to

the formation of self protecting thin

oxide film.

The thickness of the thin film can be

increased by placing the material in

aqueous solution containing 15-25%sulfuric acid and is called anodizing.

CORROSION RESISTRANCE


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The high strength alloys like Al- Cuand

Al- Znalloys are clad with commercial

aluminum or Al-Mg-Si to get better

corrosion resistance and this process iscalled Alcladding.

The normal cladding thickness per side

is 1 to 2%of the thickness of the

base metal sheet.



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Cladding is a process of producing

composite of the coating slabs and the

core ingot.

This is done by mechanically attaching

the coating slab and the alloy core ingotand the chemical bonds are produced by

hot rolling.


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TITANIUM

TITANIUM ALLOYS

TITANIUM AND ITS ALLOYS


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Titanium is produced from TiO2.

The melting point of titanium is 1720C.

It exists in HCP structure (

) at room

temperature and transforms to BCC(

)at 882C.

TITANIUM


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It has higher specific strength, good

corrosion resistance and other high

temperature properties.

An adherent protective TiO2

film

provides excellent resistance to

corrosion below 535C.

TITANIUM


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Above 535C the film breaks and small

atoms such as Carbon, Oxygen,

Nitrogen and Hydrogen embrittle the

titanium.

It is used in chemical processing

equipment, airframes, marine

components and biomedical implants

such as hip prostheses.

TITANIUM

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Alloying elements provide solid solution

strengthening and change the allotropic

transformation temperature.

Addition of Sn, Zrprovide solid solution

strengthening without affecting the

transformation temperature.

TITANIUM ALLOYS


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Al, O, H, etc. increases the

transformation temperature (i.e,

) and are calledstabilizers.

V, Ta, Mo and Nb lowers the

transformation temperature are called

stabilizers

.

TITANIUM ALLOYS


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Single phase alpha alloys are weldable

and having good ductility.

Two phase alloys are stronger than

single phase - alloysbecause BCC is

stronger than HCP .

TITANIUM ALLOYS


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The important two phase alloy is Ti

6Al 4V.

Used for making airframes, rockets, jet

engines, missile fuel tanks, human

implants, etc.

TITANIUM ALLOYS

engineering alloys(non ferrous)

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