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Adhesion of Cu electroplating to brass or 304 stainless steel

I am developing a micro scale electroforming process to create tooling for embossing plastic. I am trying to decide what substrate to deposit Cu onto in a Cu acid bath. I am wondering about the adhesion of Cu to brass versus 304 stainless steel. Which one will I get the best adhesion with assuming the surfaces are prepared equally well. Also, what type of anode should I use if I plate onto 304 stainless?

Eddie Blackwell
Engineering Student - Corvallis, Oregon, USA
2004

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When one speaks of electroforming, he is usually speaking of following the same processes as electroplating, but discarding the substrate and using the plating itself as the final object. So usually you are looking for adhesion that is good enough that the electroform will not spontaneously pop off during processing and get ruined, but not so good that it is impractical to remove the electroform from the substrate.

So I'm a little confused about your desire for the "best adhesion". I think that perfect adhesion (cannot be separated at the interface) to either substrate is possible, but activation of stainless steel is trickier so I would opt for the brass. The anode material would not depend on the substrate; oxygen-free or phosphorized oxygen-free copper anodes would be used.

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