Process for metal plating on aluminum and aluminum alloys

Abstract

Metal plated aluminum product with good adhesion between aluminum substrate and plated metal are found to be producible by the process which comprises: electrolyzing aluminum or aluminum alloys by A.C. or superimposed A.C. and D.C. in an electrolytic solution capable of producing a growth type or barrier type anodic oxide coating onto the surface of the aluminum or aluminum alloy and comprising an aqueous solution containing a water-soluble acid and a water-soluble heavy metal salt, thereby to impart good adhesion properties to the aluminum or aluminum alloy surface and render it suitable as a substrate for plating of additional metal thereon, metal plating on the resulting aluminum substrate, and subjecting said plated substrate to a heat treatment to enhance the adhesion between the substrate and the additional metal plated thereon.