Focus: GS III: Science and Technology
Why in News?
New technique of corrosion-resistant nickel alloy coatings can replace toxic chrome plating
About the technique:
- Scientists at the International Advanced Research Centre for Powder Metallurgy & New Materials (ARCI) have developed a lab-scale process for the deposit of novel nanostructured Nickel alloy coatings.
- The process can be used as a replacement for environmentally toxic chrome coatings and is suitable for high-performance materials in engineering applications, specifically in the plastic ware industry.
- The process uses a pulsed current electroplating, which is environmentally benign with high production capacity.
- The team used electric current in the form of pulses 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.
- The pulsed current effect results in nano-crystalline coatings with high hardness (700-1200 HV) and wear resistance.
- The coatings are virtually porosity free, crack-free with minimal hydrogen uptake.
- The coatings are extremely corrosion-resistant and can 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 compared to conventional chrome plating.