plating, anodizing, & finishing Q&As since 1989
Alternative to Nickel Plating for pump seal wear resistance
January 11, 2012
Q. We have a pump shaft that is SS with nickel plating for wear resistance against a pump seal. Does anyone know of an alternate surface treatment or finish that will give it comparable hardness? The shaft manufacturer is having trouble with the plating process.
engineer - Grand Rapids
A. Hi, Gary.
Nickel plating may or may not be the ideal finish for this application, but changing a finish specification because the supplier doesn't know how to do it properly, is rarely the best approach. Sending some sample parts out to unquestionably competent plating shops might be a better way to go.
It's not clear to me, and may not be clear to you yet, whether this is electrolytic nickel plating or electroless nickel plating. Electroless nickel plating exhibits outstanding corrosion resistance and wear resistance that it will be hard for any other finish to match. Low phosphorous electroless nickel is best for wear. There are more exotic and expensive coatings such as electroless nickel with hard particles, hard chrome plating, and PVD hard coatings . . . but with the limited info we have so far, low phosphorous electroless nickel sounds most promising to me. Plus, I'm not sure that you need the expense of stainless shafts if they will be electroless nickel plated.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey