Metal finishing Q&As since 1989
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Purpose of copper flash plating
My question s quite basic:
Company uses Gold plating over nickel over copper flash on machined (turned) components made of various copper alloys including C360 and BeCu (UNS 17200). One of our new vendor's asking if it is OK to foregoing copper flash step on part, that is stamped from BeCu.
Myself not being a plating expert, I am curious if I am opening Pandora Box allowing them to skip copper flash?
Any opinions?
designer - Boston, Massachusetts
November 12, 2010
Dear Mark,
Yes, you could open up that box. The Cu-flash is supposed to overplate over Be-rich (segregations) areas and provide an even surface for the Nickel, thereby reducing the porosity of the Nickel (and the gold) layer, which will lead to reduced corrosion in the longer term. If your supplier does porosity tests and guarantees you an equal behaviour plus the guarantee to pay your field failures, I would allow him, but only after all has been agreed in written documents and your customers agreed as well.....I guess in that case a complete requalification will be needed.
Best regards,
Harry
Harry van der Zanden
- Budapest, Hungary
First of two simultaneous responses -- November 20, 2010
Mark,
Beryllium has a high affinity for oxygen. They oxidized easily. That's the reason why after acid activation, a copper strike is applied prior to Nickel followed by Gold plating. For BeCu substrate, I've tried both methods, with and without the copper strike. Both have not shown any detrimental results. Good Luck.
- Penang, Malaysia
Second of two simultaneous responses -- November 22, 2010
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