Cathode growth stability of electrodeposited metal matrix particulate composites

A simple model is proposed correlating operating conditions (electrochemica l kinetic behaviour of the metal matrix deposition process, concentration o f suspended particles, particle dimensions, hydrodynamic conditions) and ca thode growth stability for electrodeposited metal matrix particulate compos ites with dispersions of non-conducting particles. Even though variations o f all the considered variables have a bearing on growth stability, the most important single effect is polarisation (as, e.g., expressed by the local Tafel slope): the deposition of metal with high polarisation makes codeposi tion possible and renders viable the achievement of sufficiently smooth and thick materials; metals deposited at low overvoltage are mostly associated with unsuccessful composite plating. The predictions of the model were con firmed with deposition experiments, cathode stability was judged according to SEM in-plane and cross-sectional micrographs as well as by roughness mea surements.