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Plating lower karat gold or underplate for wear resistance

I am manufacturer of gold plated costume jewelry - we're also producing bracelets. The problem is that after a few weeks customers easily make many scratches on surface. We are using 18K gold bath - layer about 2- 2,5microns. My question is simple. Is it possible to electroplate some "underplate" metal (yellow color) under expensive 18K gold? Something like less karat gold (8K) in thick layer or something like "yellow silver" (stupid, isn't it?). Thanks for reply.

Otto Rupert
manufacturer- producer - Jablonec nad Nisou, Czech Republic
2004

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It would be possible to do an underplating of brass, which could be very yellow and gold-like. But the conventional way of solving this is with an overplate of titanium nitride instead. The equipment cost may be out of your range though.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2004

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Hello,

I have one question. Is it possible to electroplate gold over TiN surface (PVD)? We are going to use TiN plating on bracelets but not on necklaces. We need this electroplating for colour matching between them.

Thanks for answer.

Daniel Vrana
jewelry manufacturer - Jablonec nad Nisou, Czech Republic
2004

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Some jewelry has been coated with titanium nitride (TiN)and then plated with gold. The advantage of this is that the TiN is gold colored, very hard and wear resistant. The principle is that the rough TiN surface is filled with the softer gold and as the gold wears off, the TiN substrate becomes more exposed, thereby offering a harder and more lubricious surface that reduces the rate of gold loss. Although TiN is a ceramic, it has unusually low electrical resistance, but this depends on how it is put down. Bulk TiN has a specific resistance of about 10-30 micro-ohm-cms, whilst PVD deposited samples are 30-100 and CVD can be between 200 and 10,000 micro-ohm-cms.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2004