A PRESENTATION ON

NON FERROUS ALLOYSPrepared ByNandlal BirleMechanical Engg. Dept.

Copper alloy1. Brasses

2. Bronzes

3. Copper – nickel alloys

1. Brasses• α phase – FCC structure• phase – BCC structure (disordered)β• ’ phase – BCC structure (ordered)β• phase – complex structure (brittle)γ

1. Brasses Zinc (Zn) is predominated alloying element for Brasses. Up to 35 % of zinc be weight is called α – solid solution. Above 35 % of zinc the β – crystal is begin to form and its

continue up to 59 % of zinc. Between 35% and 47% of zinc, a mixture of   and  -crystals α β

exists. Above 50 % of zinc the γ – crystal is begin to form and its

continue up to 79 % of zinc. 51% and 59% zinc consist of mixtures of   and  -crystals.β γ

Types of brasses1. α – brasses

1. Red α – brasses2. Yellow α – brasses

2. α – β brasses1. Muntz metal2. Naval brass3. Leaded brass4. High tensile brass

3. Cast brasses1. Cast red brass2. Cast yellow brass

Types of brasses1. α – brasses

1. Red α – brasses2. Yellow α – brasses

Is quite ductile and soft at room temperature due to this they are excellent cold working alloys.

They also have good corrosion resistance.

α – brassesRed α – brasses

Name Cu & Zn % respectively

Properties Uses

Gilding metal 95 & 5 Gold color Making coins, medals, jewellery base for gold plating

Commercial bronze

90 & 10 Cold and hot working properties

Costume jewellery, lipstick cases and grill work

Red brass 85 & 15 Good corrosion resistance

Condenser and H.E. tubing, electrical sockets

Low brass 80 & 20 - Musical instruments, flexible hoses

α – brassesyellow α – brasses

Name Cu & Zn % respectively

Properties Uses

Cartridge brass

70 & 30 Good strength and ductility

Cartridge case, radiator cores, tanks, flash light shells

Yellow brass 65 & 35 Good strength and ductility

Reflectors, fasteners and springs

Admiralty brass

71 & 23 & 1 Sn

Good strength and corrosion resi.

Condenser and H.E. tubing in steam power plants

α – brassesyellow α – brasses Aluminium brass The yellow α – brasses brass is corrosive in marine

environment is called dezincification. Dezincification involves dissolution of the alloy, and

deposition of porous non-adherent copper. This penetrates the cross section of the metal and leads

to leakage. 2 % aluminum and small amount of As inhibit

dezincification.

α – brassesyellow α – brasses Aluminium brass contains 76Al-22ZN-2Al-0.04As. It forms a self-healed tenacious film in contact of sea

water. It is widely used in marine applications.

α – β brasses α – β brasses contains 34 – 46% Zinc. This alloy contains two phase α and β’. β’ phase is hard

and brittle at room temperature. β’ phase makes it hard due to this it has low capacity of

cold working. This is best shaped by hot working processes.

α – β brasses Types

Name Cu & Zn % respectively

Properties Uses

Muntz metal 60 & 40 Cant be rolled or forged

Condenser tube, valve stems, brazing rods.

Naval brass 60 & 39 & 1 Sn

Good salt water corrosion resistance

Marine hardware, propeller shaft, piston road and valve stems

Leaded brass Additional 1-3% lead

Good machinability

Machine stock and gears

Cast brass1. Cast red brass – 85 % Cu, 5% Sn , Pb and Zn.

1. It has fair strength and corrosive resistance.2. Also got antifriction prosperities. 3. Used in pipe fitting, bearing and small gears.

2. Cast yellow brass – 60% Cu, 38% Zn, 1%Sn and 1% Pb.1. Low cost2. Used in hardware fitting.

Bronzes Term bronze was previously applied for a copper alloy, with tin

as major alloying element. The simplest bronze contains 88% Cu with 12% tin. Bronze is any copper alloy containing other then zinc or

nickel. Other alloying elements like phosphorous, lead, nickel etc. are

also added to obtain favorable properties. Other than tin, elements like aluminium, silicon or beryllium

are also alloyed with copper producing different bronzes. Zinc also may be present in these alloys in relatively smaller

amounts.

Properties & Uses Bronzes are softer and weaker than steel. Corrosion resistance, heat and electric conductivity are also better

than steel, while the cost is higher than steels. Compared to brasses, these are having lower coefficient of friction,

higher strength, toughness, corrosion resistance and also higher cost.

Bronze is having good castability and anti-friction or bearing properties.

Bronzes are widely used for different purposes like bearings, springs, industrial castings, bells and statues.

Types Tin Bronze:

Sn present 1 % at room temperature and 13.5% at 798 ºC in α-solid solution

Gun metal: an alloy of copper (88%), tin (10%), and zinc (2%). Originally used chiefly

for making guns Aluminium bronze:

contains 4 – 11% aluminum. It has finest color and also called imitation gold)

Silicon bronze: Beryllium bronze:

contains up to 2.5% of beryllium. It has much higher tensile strength than other bronzes.)

Aluminium Aluminium occupies the third place among commercially used

engineering materials. It has low density, low melting point and high electrical and thermal

conductivities. It has low strength and hardness, but high ductility and malleability. On exposure to atmosphere, it forms a strong film of aluminium oxide on

its surface, which prevents further oxidation and corrosion. It is employed for lightly loaded structures and for electrical cables and

similar items. Aluminium has good machinability, formability, workability and

castability. It is non-magnetic, non-toxic, easily available and less expensive. The main drawback is its low strength and hardness.

Al-Cu phase diagram

Aluminium alloys Maximum solubility of copper in aluminium is 5.65% at

550OC and it reduces to 0.45% at 300OC. Alloys containing between 2.5 and 5% copper will respond

to heat treatment by age hardening. Due to the increased strength, aluminium alloys are widely

used in commercial applications. Two main groups of aluminium alloys are wrought alloys

and casting alloys.

Aluminium alloys Wrought alloys : Al-Mn and Al-Mg alloys form homogenous

solid solutions and are characterized by comparatively lower strength and high ductility. Other examples are avial (Al-Mg-Si) and duralumin (Al-Cu-Mg).

Casting alloys: The best known casting alloy is the silumin alloys. Alloys of Al and Cu also are suitable for casting. Many of the casting alloys are heat treatable.

Aluminium alloys Duralumin: A typical composition is 94% Al, 4% Cu

and 0.5% each of Mg, Mn, Si and Fe. High tensile strength and electrical conductivity. Widely used for aeroplanes, surgical and orthopedic

equipments. Y-alloy: Composition of this alloy is 92.5% Al, 4% Cu,

2% Ni and 1.5% Mg. High strength and hardness even at high temperature such as

200oC. Used for cylinder heads and crank cases of engines.

Aluminium alloys Magnelium: The major alloying elements in this alloy

are magnesium and copper with Ni, Sn, Fe, Mn and Si in small amounts. Better tensile strength and machinability, but it is brittle. Used by aircraft and automobile industries.

Silumin alloys: Alloys based on Al-Si system are known as silumin alloys. A typical silumin is the eutectic alloy with 88% Al and 12% Si. Having good castability, corrosion resistance, high ductility

and low density.

Titenium Titanium has two allotropic forms: upto 880OC, it exists

as a-titanium hexagonal close packed structures (HCP)and at higher temperatures as -titanium (BCC)β

It is a strong, ductile and light weight metal, density of pure Ti is 60% of steel.

High corrosion resistance and high strength at elevated temperatures and widely used as a structural material.

Suitable for cold and hot working and has good weldability.

Machinability is much inferior to steel

Titanium alloys The most important alloying elements for titanium are

Al, Cr, Mn, V, Fe, Mo and Sn which considerably increase the mechanical strength.

Higher creep resistance, higher fatigue strength, highest specific strength and good corrosion resistance.

Responds to heat treatment by precipitation hardening. Ti-6Al-4V is the most widely used alloy, accounting for

about 45% of total titanium production.

Uses of Titanium Alloys

Used for aerospace structures and turbines due to the high specific strength, corrosion resistance and strength at elevated temperature.

Titanium is used in the construction of leaching and purification plants for cobalt production.

Due to the higher corrosion resistance, titanium is also used in various chemical processing equipments, valves and tanks.

Uses of Titanium Alloys

Used for aerospace structures and turbines due to the high specific strength, corrosion resistance and strength at elevated temperature.

Titanium is used in the construction of leaching and purification plants for cobalt production.

Due to the higher corrosion resistance, titanium is also used in various chemical processing equipments, valves and tanks.

Magnesium Magnesium has the HCP crystal structure. It is lighter and less ductile than aluminium. It is having poor modulus of elasticity, poor resistance

to wear, fatigue and creep. Its response to strengthening mechanisms also is

relatively poor. Solubility of aluminium in magnesium increases with

temperature This alloy responds well to age hardening also

Magnesium Alloys Addition of aluminium to magnesium increases

strength, hardness and castability. Addition of manganese to magnesium has very little

effect on the mechanical properties, but it improves the corrosion resistance.

Magnesium-aluminium-zinc alloys have higher mechanical properties and good corrosion resistance.

In general, magnesium alloys have poor ductility and formability, but poor fatigue and stress corrosion resistance.

Uses Magnesium Alloys