Commercially Pure Nickel Properties, Fabrication and Applications of Commercially Pure Nickel
Commercially pure or low alloy nickel finds its main application in chemical processing and electronics.
Because of pure nickel's corrosion resistance, particularly to various reducing chemicals and especially to caustic alkalis, nickel is used to maintain product quality in many chemical reactions, particularly the processing of foods and synthetic fibre manufacture.
Properties of Commercially Pure Nickel
Compared to nickel alloys, commercially pure nickel has high electrical conductivity, a high Curie temperature and good magnetostrictive properties. Nickel is used for electronic lead wires, battery components, thyratrons and sparking electrodes.
Nickel also has good thermal conductivity. This means it can be used for heat exchangers in corrosive environments.
Table 1. Properties of Nickel 200, the commercially pure grade (99.6% Ni).
|Annealed Tensile Strength at 20°C||450MPa|
|Annealed 0.2% Proof Stress at 20°C||150MPa|
|Specific Heat||456 J/kg. °C|
|Co-Efficient if Expansion (20-100°C)||13.3x10-6m/m.°C|
Fabrication of Nickel
Annealed nickel has a low hardness and good ductility. Nickel, like gold, silver and copper, has a relatively low work hardening rate, i.e. it does not tend to become as hard and brittle when it is bent or otherwise deformed as do most other metals. These attributes, combined with good weldability, make the metal easy to fabricate into finished items.
Nickel in Chromium Plating
Nickel is also frequently used as an undercoat in decorative chromium plating. The raw product, such as a brass or zinc casting or a sheet steel pressing is first plated with a layer of nickel approximately 20µm thick. This gives it its corrosion resistance. The final coat is a very thin 'flash' (1-2µm) of chromium to give it a colour and tarnish resistance that is generally regarded as more desirable in plated ware. Chromium alone would have unacceptable corrosion resistance because of the generally porous nature of chromium electroplate.
|Material||Nickel - Properties, Fabrication and Applications of Commercially Pure Nickel|
|Composition:||>99% Ni or better|
|Property||Minimum Value (S.I.)||Maximum Value (S.I.)||Units (S.I.)||Minimum Value (Imp.)||Maximum Value (Imp.)||Units (Imp.)|
|Atomic Volume (average)||0.0065||0.0067||m3/kmol||396.654||408.859||in3/kmol|
|Bulk Modulus||162||200||GPa||23.4961||29.0075||106 psi|
|Modulus of Rupture||70||935||MPa||10.1526||135.61||ksi|
|Shear Modulus||72||86||GPa||10.4427||12.4732||106 psi|
|Young's Modulus||190||220||GPa||27.5572||31.9083||106 psi|
|Latent Heat of Fusion||280||310||kJ/kg||120.378||133.275||BTU/lb|
|Maximum Service Temperature||510||640||K||458.33||692.33||°F|
|Minimum Service Temperature||0||0||K||-459.67||-459.67||°F|
|Resistivity||8||10||10-8 ohm.m||8||10||10-8 ohm.m|
|Resistance Factors||1=Poor 5=Excellent|
|Oxidation at 500C||5|
Source: Abstracted from Handbook of Engineering Materials, 5th Edition.
For more information on this source please visit The Institute of Materials Engineering Australasia.