Palladium-silver alloys for electrical contacts - deposited from ammoniacal bath contg. palladium tetramine complex, silver di:amine complex and organic sulphur cpd.

摘要

Pd-Ag alloys for electrical contacts are electrolytically deposited from an ammoniacal bath contg. Pd as a tetraqmine tetramine complex and Ag as a diamine complex, with organic S cpd. as brightening agent. Pd comprises 5-50g/l, Ag2-40 g/l, and S cpd. 1-50 g/l, as an aliphatic or aromatic mercapto-cpd.. Bath pH is greater than 8. Mercapto-cpd. is e.g. mercapto-acetic acid, mercapto-propionic acid, thioglycerine etc. and addn. can also be made of an amide of an aliphatic carbonic acid. ADVANTAGE - Ductile, pore-free and crack-free coatings are formed.