Abstract
The porosity of gold deposited from alkaline cyanide, acid citrate, and neutral phosphate baths, has been investigated as a function of operating conditions and composition. All operating conditions, and all except one of the composition variables investigated, can markedly affect porosity. Two bright golds (Au-Ag and Au-Ni) were, other things being equal, less porous than the equivalent dull coatings. The low metal content (Au=8 g/I) often adopted, whilst not precluding the plating of coatings of very low porosity, makes the optimum operating conditions critical in all baths.