Electrodeposition of silver-cadmium alloys from cyanide electrolytes

Electrodeposited layers of silver-cadmium alloys are reported to have incre ased hardness, electrical conductivity and tarnish resistance compared to s ilver. The standard electrode potentials of silver and cadmium are too far apart to permit codeposition from simple salt solutions, suitable complexin g is necessary to bring the deposition potentials closer and facilitate cod eposition. Results of the investigations with cyanide complexed solutions a re presented in this paper. Electroplating experiments with varying concent rations of metal ions and operating conditions have shown the possibility o f depositing alloys with a range of compositions. Characterisation of the d eposits has been by X-ray diffraction, scanning electron microscopy and mic rohardness measurements. Voltammetric studies show the deposition of alloys of solid solution type at low concentrations of cadmium and a mixture of p hases at higher concentrations.