Induced codeposition .2. A mathematical model describing the electrodeposition of Ni-Mo alloys

A steady-state mathematical model was developed to predict the behavior of the induced codeposition of Ni-Mo alloys in the kinetic and mass-transport controlled regions on rotating cylinder electrodes. The kinetic regions were characterized by a simple Tafel expression. A Nernst boundary layer representation described the mass transfer of ions through a diffusion layer. The governing features of the induced codeposition mechanism included soluble nickel acting as a catalyst to the molybdenum deposition and the generation of an absorbed intermediate species on the electrode surface. The resulting alloy composition was simulated for two electrolytes over a wide range of current densities and electrode rotation rates. The model predictions agreed with the observed trends in the experimental data.