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How to achieve a thickness of 2.5 mils of Nickel/Chromium on a part

I have a customer who is requesting a plating thickness of 2.5 mils of nickel/chromium on iron cast parts. I am having a difficult time achieving the thickness, and I am getting a severe dog-bone effect be cause of the parts high and low density areas. This is causing the part to be unusable. In an effort to come up with a happy medium for my customer, what is the usual thickness this process is applied at. Why would they be asking for such thickness.

Victor Quinones
plating shop - Indian Trail, North Carolina, USA
November 15, 2011

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You do not say what you are using for the nickel and the chrome solutions.

I would try increasing the agitation, particularly the air agitation directly under the parts.
Then I would try to make the tanks a bit less efficient by lowering the amperage very slightly. See what a 0.1 volt drop does.
Finally, I would lower the pH of the nickel by 0.1 pH.
Do not get carried away with major changes.

For chrome, Can you change your anode setup IE: closer in the low density areas. I really like conforming anodes. They take an initial bit of work to set up, but the much higher plate rate with nearly uniform plating makes it well worth it, particularly if this is a long term job. No rejects is really nice also.

James Watts
- Navarre, Florida
November 17, 2011

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I will go with James but add ... maybe you can increase the anode cathode distance a bit. Analyse the nickel bath soln and adjust to the optimum. Regards

T.K. Mohan
plating process supplier - Mumbai, India
November 28, 2011