GALVANOSTATIC PULSE AND PULSE REVERSE PLATING OF ZINC-NICKEL ALLOYS FROM SULFATE ELECTROLYTES ON A ROTATING-DISC ELECTRODE

Galvanostatic pulse and pulse reverse techniques have been used to stu dy the plating of zinc-nickel alloys in the presence of nonyl phenyl p olyethylene oxide. The effects of average current density, rotation sp eed of disc electrode and the presence of nonyl phenyl polyethylene ox ide in the electrolyte on deposition of zinc-nickel alloys were evalua ted. Zinc-nickel plating bath solution chemistry was studied by determ ining the equilibrium concentrations at various pH levels. It was foun d that the alloy composition was determined by solution equilibria, ma ss transfer of the electroactive species within the diffusion layer an d by the surface coverage of nonyl phenyl polyethylene oxide.