Abstract
Studies were made of the effects of nickel, zinc, and cadmium as impurities contained in cyanide baths on silver plating.
Measurements of cathodic polarization curves, absorption spectra, and electric conductivity revealed that all kinds of the three metals produced complex cyanides. The polarization of the bath containing nickel was less noble and that of zinc or cadmium was nobler than that of the originall bath.
The results of studies on electrodeposited silver by appearance, X-ray diffractiometry, and electron microscopy showed uneven brightness at lower than 0.5g/l of nickel concentration. very rough surfaces were observed by preventing the 3-dimensional nuclear growth over the whole range of nickel concentrations.
Zinc or dadmium produced more uneven brightness with the increase of its concentration at higher than 0.5g/l, when coarse crystal grains were observed.
Orientation of crystals was not observed in any of these silver platings.
