Non-Ferrous Metal: Nickel & Ni Alloys

Presented By:-Deepam Goyal

Department of Mechanical EngineeringNITTTR , CHANDIGARH

Non-Ferrous Metals

Introduction to Nickel

Production of Nickel

Extraction of Nickel

Classification of Nickel Alloys

References

CONTENTS

• In metallurgy, a non-ferrous metal is any metal, including alloys, that does not contain iron in appreciable amounts.• They are generally suffer from hot-shortness, possess lower strength at lower temperatures.

Properties:-• Low density• Higher thermal & electrical conductivities, magnetic properties• Attractive colours• Softness & facility of cold working• Good formability• Corrosion resistance• Fusibility & ease of casting and fabrication.

Non-Ferrous Metals

Contd..

Non-Ferrous Metals Ferrous Metals

• Don’t Contain iron as base

• Lower Melting Points

• More expensive

• More Shrinkage

• Contain iron as base

• Higher Melting Points

• Less expensive

• Less shrinkage

General:-• Belongs to the transition metals. • It is hard and ductile• Crystal structure - FCC• Atomic number - 28 • Atomic weight - 58.71 • Density ( ) - 8.89 • Melting point (°c) – 1455• Boiling point(°c) – 2913

Note:-• It is only one of four elements that are magnetic at near or room temp.• Its Curie temperature is 355°c (means it is non-magnetic above this temp.)

Introduction To Nickel

3/ cmg

Properties:-• Silvery shiny appearance • High toughness and ductility• Good high and low temperature strength• High oxidation resistance • Good corrosion resistance (slow rate of oxidation at room temp.)• It is Ferro-magnetic.

Limitations:-

• Not mixed with cheap alloying elements

• Relatively high cost.

Contd..

Applications:-

• Ni and its alloys are used in making coins.• Nickel is used in rechargeable batteries such as Ni-Cd & in magnets.• Its alloys are also used for armour plate and burglar proof vaults.• Chemical plant, heat exchanger, reaction furnace, rotary kiln, turbine blades.• Used as alloying elements in stainless steels etc.• Ni and its alloys are frequently used as catalysts for hydrogenation reactions (Raney nickel)• Ni is used as a binder in the cemented tungsten carbide or hard metal industry.

Contd..

First discovery of nickel mineral by the German was mistakenly misunderstood to be rich-copper mineral.

There are three major types of Nickel deposits (sources):

1) Nickel-copper sulphide

2) Nickel silicates

3) Nickel laterites and serpentines

Ni-laterite Deposits

Production of Nickel

Extraction Process

There are different types of nickel and nickel alloys;

Commercially pure nickel

Nickel-copper alloys (Monels)

Nickel-chromium alloys

Nickel-base superalloys

Nickel-iron superalloys

Classification of Ni & Ni-Alloys

• High purity nickel contains 99.99% Ni.• Commercially pure nickel contains 99.5% Ni (+Co). • Microstructure consists of solid solution phase in annealed condition.

Properties:-•Good mechanical properties and retains its strength at elevated temperature. •Excellent resistance to most corrosive environment.Applications:-• Food processing equipment• Electrical & electronic parts • Caustic handling equipment.

Commercially Pure Nickel

• Ni and Cu form complete solid solution.

• Ni-Cu alloy contains 67%Ni and 33%Cu, called Monels.

Two types of Monels are found :-

1) Monel Metal:- (Metal Treated)• consists of (67% Ni + 30% Cu + small amounts of Fe, Mn, Si & C).

Properties• High strength and toughness over a range of temperature. • Good weldability • Excellent corrosion resistance• Resistant to Sea Water, Chlorine

Nickel Copper Alloys (Monels)

Applications• Steam turbine blades (UTS-525 Mpa & Yield Strength-230 Mpa)• High temperature valves• Centrifugal pump impellors & water meter parts.

2) K-Monel:- (age hardened)• Consists of 66% Ni + 29% Cu + 2.57% Al +Mn + C).

Properties• wholly Non-magnetic• Al increases strength & hardness above that of monel.

ApplicationsPump shafts, springs & valve stems etc.

Contd..

• Cr forms solid solution with Ni up to~30% at room temperature. • High corrosion resistance is due to high Cr addition.

1) Inconel 600:-• consists of (79.5% Ni + 15.5% Cr + 8% Fe) is a standard engineering alloy. Properties• High corrosion resistance at high temp. • High strength and workability. • Difficult to machine.

Applications• Gas turbine combusters and blades.• Chemical and food processing equipment.• Furnace muffle & rocket skins.

Nickel Chromium Alloys

2) Nichrome:-• consists of 80% Ni + 20% Cr.

Properties• high melting point• high electrical resistivity• good stability from deforming

Applications• resistance heating coils• rocket igniters• jewellery casting supports• ceramic manufacturing industry

Other Ni-Cr alloys are Inconel 601 and 625 with improved properties.

Contd..

• High temperature heat-resistance alloys, which can retain high strengths at elevated temperatures.

There are three types of Ni-base superalloys; • Ni base, Ni- iron base and cobalt base. The alloys contain high Cr with Ti, Al to from precipitates and additions of Mo, Co, Nb, Zr, B, Fe. • Microstructures are complex.

Properties• Heat resistant and high strength at high temperature (760-980°C). •Good corrosion & oxidation resistance.

Nickel Base Superalloys

The major phases present in the nickel-base superalloys:1) γ (gamma) phase –the continuous matrix of FCC austenite.2) γ’(gamma prime) phase –the major precipitate phase (more cubic shape). 3) Carbides –various types, mainly and MC. (M – metal).

Applications• Aircrafts, space vehicles, rocket engines• Industrial gas turbines, high temp applications. • Nuclear reactors, submarines. • Steam power plants, petrochemical equipment.

Contd..

623CM

• Fe is added to replace some of Ni as it has lower cost. - lowering the properties as compared with nickel base super alloy, therefore it is used at lower temperatures.• Ni-Fe superalloys contains 25-45% Ni + 15-60% Fe. • Higher Ni content increases operating temp (upto815oC), due to improved stability but more costly.•Microstructure consists of austenitic FCC matrix and can be strengthened by solid solution strengthening(Mo, Cr), and precipitation hardening(Ti, Nb, Al) by forming intermetallic phases.

Examples: Inconel707, 718, 901.

Nickel Iron Superalloys

1) German Silver:-Consists of 60% Cu + 20% Ni + 20% Zn.

Properties• Hard, white & ductile• Good mechanical & corrosion resistance

Applications • silver plated cutlery• zippers & jewellery• musical instruments• pipe fittings• ornamental work of cars

Some other Nickel alloys

2) Haste alloy:-Consists of 45% Ni + 16% Cr + 15% Mo

TYPES : A,B,C,D & its variants

Properties• high wear resistance• high corrosion resistance• high stress service

Applications• Bearings• Pressure vessel linings• chemical reactor pipes

Contd..

REFERENCES

Kalpakjian Seope, Schmid Steven R.: “Manufacturing Engineering & Technology” Pearson Education India, 2009, pp 183-185.

Sharma, P.C. ”A textbook of production Technology”. 7. New Delhi: S.Chand & Company Ltd, 2011, 60-62. Print.

Smith, W.F. “Structure and properties of engineering alloys”, second edition, 1993, McGraw-Hill, ISB 0-07-59172-5.

Davis, Joseph R. ”Nickel, Cobalt & their alloys”. United States of America: ASM International, 2000. 5-192. Print.

Email ID :- bkdeepamgoyal@gmail.com