The application of pulse electrolysis to single metal deposition is reviewed. In comparison with deposits obtained from DC electrolysis, those obtained by pulse electrolysis with pulsed current (PC), periodic reverse current (PR) and asymmetric alternating current (AAC) show a far wider range of change in such properties as hardness, porosity and ductility. Each of the plating parameters-cathodic peak current density ip
, on-time Ton
, off-time Toff
, anodic peak current density iap
- strongly influences the properties of the deposits. A high ip
, which results in smaller grain size and greater brightness has the effect of increasing hardness relating to structual modification. This is due to the high overpotential that developes along with high ip
. A short Ton
results in the formation of uniform thin diffusion layers that produce smooth deposits. A long Toff
controls the morphology of the deposits because it is during Toff
that the recovery of ion concentration, the dissolution and recrystallization of deposits, and the adsorption of anions and surfactants occur. While ductile but soft deposits have been obtained by pulse plating with an iap
in additive-free baths, it seems fairly well established that the use of pulse plating parameters that result in grain refinement will also lead to a reduction in porosity of deposits as well as increase in ductility.
Pulse electrolysis appears to have great potential for obtaining electrodeposits with a wide range of properties.