Download - Nickal and its alloys
Non-Ferrous Metal: Nickel & Ni Alloys
JIM ALEX ME S3 SBCE PATTORMETALLURGY
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:- Fifth most abundant element in earth
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. Having FCC crystal structure.Limitations:-
• Not mixed with cheap alloying element.
•Relatively high cost.
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Applications
85% of metallic nickel used in combination with other metals alloys
1. Used in gas turbines and rocket engines
- easy to work and can be drawn into wire - resist corrosion even at high temperatures
Nickel (Ni)
gas turbines
rocket engines
2. Used for propeller shaft in boats and desalination plants- Monel: an alloy of nickel and copper- Hard, can resist the corrosion by sea water
3. Used to make stainless steel- used very widely in the home, in architecture,- in health care, in food processing and - throughout industry.
Nickel (Ni)
Monel
Stainless steel cutlery
4. Used to make Nickel-cadmium batterySmall NiCd dry cells are used for portable electronics and toys rechargeable batteryoften using cells manufactured in the same sizes as primary cells
Nickel-cadmium battery
Nickel (Ni)
5. Used in nickel-copper alloys and nickel silver
nickel-copper alloys: - improves strength and corrosion resistance - good ductility is retained - excellent resistance to marine corrosion and
biofouling Nickel silver - used in better-quality keys, making musical
instruments (e.g. cymbals, saxophones), production of coins.
- marine fittings and plumbing fixtures for its corrosion resistance, and heating
Nickel (Ni)
Nickel silver coins
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:- • 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.
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1)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
Nickel Chromium Alloys
• 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
Applications• Aircrafts, space vehicles, rocket engines• Industrial gas turbines, high temp applications. • Nuclear reactors, submarines. • Steam power plants, petrochemical equipment.
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1) German Silver:-Consists of 60% Cu + 20% Ni + 20% Zn.
Properties• Hard, white & ductile• Good mechanical & corrosion resistance
Applications • silver plated cutlery•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
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