Summary for anodizing and electroless nickel Discussion
Anodizing and electroless nickel on same piece is generally not done over the same exposed area, because Ted Mooney, P.E. says the hard anodizing process will destroy any electroless nickel or nickel plating already present. His practical advice is to reverse the sequence: mask off the area that must be plated, hard anodize the rest of the part, and then selectively nickel plate the masked area afterward. The thread is brief and does not present a conflicting view, but it clearly indicates that process order and masking are critical if both finishes are needed on one component.
Nadcap Chemical Processing Auditor – PRI, traveling
Process Engineer / Chemist – Denver Metal Finishing, Colorado
Q. I’ve been looking at different platings that are used on parts and what benefits they add to the part when run in an engine. Electroless nickel plating (ENP) is a coating is a service that doesn’t use electricity as a catalyst to plate the material. I was wondering if the whole of an aluminium alloy engine component can be plated using ENP and then machine off in a selected area to produce a groove exposing the aluminium alloy again to then get that newly machined groove hard anodised without masking the rest of the part with lacquers and tapes etc. Would the EN plating act like a mask when in the anodising tank? I have read that it’s a nickel-phosphorus that builds upon the surface of the Al alloy and has some electrical insulating properties depending on the phosphorus content. How would the hard anodising process react to the ENP layer built up?
If anyone has any experience/information or ever tried this that would be helpful.
Joshua Sidhu
Prod Eng – Northampton
January 14, 2022
A. Hi Joshua. Unfortunately that won’t work. Although electroless nickel may be slightly less conductive than some other metals, it’s resistance is nowhere close to what would be needed to act as a mask for anodizing.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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January 2022
A. Speaking from the school of Hard Knox, the hard anodizing process will destroy any ENI or Ni plating. Typically one would mask off the the area requiring plating, hard anodize, and then selective Ni plate the masked off area.
Marc Green
anodizer – Boise, Idaho
February 2, 2022