GB1488559A - Method of plating a substrate - Google Patents

Abstract

1488559 Electro-plating DAINI SEIKOSHA K K 16 July 1975 [17 July 1974] 29888/75 Heading C7B A metal or alloy substrate which developes a stable oxide film, such as stainless steel or Ti, Ta, Nb, Zr, Al or alloy thereof, is plated by dry plating e.g. ion plating thereon a first metallic layer, e.g. Au, Pd, Pt or Cu by an ion plating process, then wet plating e.g. electro-plating a second metallic layer of Au, Ag, Pt, Pd or Rh or alloy thereof such as Pd-Ni or Au-Ag on to the first; a third metallic layer (preferably of the same metal as that of the second) may be deposited e.g. by electro-plating on to the second, e.g. Au-Ni-In alloy on to Au-Ag alloy. The substrate may be an alumite treated watch case of Al alloy containing 2% Mg or a watch band of Al alloy containing 4% Cu. In an Example Ti plates may be buffed and cleaned with trichloroethylene, prior to ion plating in a bell jar under argon at 5 x 10<SP>-3</SP> Torr pressure wherein D.C. of 2,000 volts is applied between the plates as cathode and an evaporating device (e.g. with Au thereon) as anode. The ion plated plates may be degreased cathodically in a bath containing Na 3 PO 4 solution, soaked in H 2 SO 4 solution and washed with water prior to electro-plating e.g. with Au.