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Selection of plating on metal for wear resistance

April 7, 2009

dear sir,

We have electroless Ni plating, hard chrome plating, PTFE coating, MOS2 coating available for metal coating. Now I want to know what are the criteria of selection of process for application of coating. I want to know which coating should be applied for which metals.

What are the parameters for selection of process?

Sanjay Kushwaha
plating shop employee - Nasik, Maharashtra, INDIA

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April 7, 2009

Hi, Sanjay. Chromium offers the greatest hardest and best lubricity and the ability to retain lubricants in it's mud-flat structure. Electroless nickel offers uniformity of thickness, excellent corrosion resistance, good conductivity, and good hardness, especially if heat treated. PTFE is very slippery, but soft and thick. MoS2 is probably a highly adhesive topical lubricant more than a coating technology.

If you can explain your situation, then readers who have broad experience with the properties of those materials may be able to help you make a selection. But materials like these have long and extensive lists of properties (hardness, melting point, softening point, recrystalization temperature where the plating loses its corrosion resistance, thermal conductivity, electrical conductivity, corrosion resistance, galvanic compatibility issues, typical coating thickness, etc.). Listing them in sufficient detail that people inexperienced with them can make the selection themselves probably requires books rather than a paragraph or two. Safranek's "Properties of Electrodeposited Metals and Alloys" should come pretty close to what you are looking for.

Good luck.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

dear sir, thanks for your response. we are doing electroless nickel PTFE composite plating on pinion mate shaft of differential of vehicle. its cost is very high we want to reduce the cost. Please let me know how to reduce cost by maintaing its quality(hardness, coeff. of friction should not be changed).

Sanjay Kushwaha
plating shop employee - Nasik, Maharashtra, INDIA
July 10, 2009