Nickel Alloy Coating

Why in news?

• A new method of deposition of Nickel alloy coatings on high-performance materials in engineering applications can replace environmentally toxic chrome coatings. The coatings obtained are also highly corrosion-resistant and useful for the plastic ware industry.
• The process used pulsed current electroplating, which is environmentally benign with high production capacity.
• They have used electric current in the form of pulses of a duration of a few milliseconds for electroplating purposes.
• The process consists of an environment-friendly electrolyte consisting of nickel and tungsten ions that is the source of strengthening elemental tungsten (W) and nickel (Ni). 
• The pulsed current is applied between the components to be coated, acting as a cathode and a non-consumable anode.

Advantages of the new method:

• The pulsed current effect was used for nano-crystalline coatings wherein high instantaneous current density for a very small duration resulted in a high rate of nucleation. 
• The coatings were virtually porosity free, crack free with minimal hydrogen uptake. 
• The use of pulsed current resulted in the nano-crystallization of nickel tungsten alloy coatings with high hardness (700-1200 HV) and wear resistance. 
• The coatings were extremely corrosion-resistant and could withstand up to 700 hrs of salt spray.
• The coatings can withstand temperatures up to 500°C without thermal softening and can improve the life of die components by at least two times than conventional chrome plating. 

Key facts about Nickel

• It does not occur freely in nature.
• It is found in association with copper, uranium and other metals.
• It is an important alloying material.

Q1) What is an alloy?

A metal alloy is a substance that combines more than one metal or mixes a metal with other non-metallic elements.For example, brass is an alloy of two metals: copper and zinc.

Source: The new technique of corrosion-resistant nickel alloy coatings can replace toxic chrome plating

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