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  for Metal Finishing since 1989
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Preferred alloy for electroplating on aluminum

We need to electroplate Cu, Ni or whatever on aluminum or some aluminum alloy. Is there a preferred alloy of aluminum for doing this? Alternatively, is there any alloy of mostly low atomic number elements (Al, Mg, C, Si, N, P, B, etc.) which is relatively easy to plate on? Is is possible that any such alloy could be plated without a zincate of anodizing step?

Thanks very much.

Stewart Griffiths
- Livermore, California, USA
2003

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All aluminum can be plated on, but some are easier than others. The simplest is pure aluminum. Avoid silicon as much a practical. 7075 is probably the worst alloy to electroplate as it has nearly 10% other elements in the alloy. For conventional electroplating, a Zincate is virtually mandatory for most platers. A double zincate is better than a single zincate. There are some binary and ternary zincate alloys that are advertised as being superior, but most contain a small amount of cyanide-so approach with caution. For small areas, brush plating has been done on some alloys by some people with fair results without zincating.

James Watts
- Navarre, Florida
2003