Kinetic study of electroless cobalt deposition on WC particles

The cobalt coating with an average thickness of 15-20 nm was uniformly plated on the surface of ultra-fine WC powders by electroless plating in the present work. The effects of electroless plating condition parameters on the deposition rate were studied. It was found that the deposition rate increased with the increase of CoSO4·7H2O content, pH value, complexing agent concentration, and bath temperature, while decreased with the increase of reducing agent (NaH2PO2·H2O) concentration. Furthermore, the cobalt deposition rate empirical equation and activation energy were determined. The results show that the activation energy (Ea) for the electroless cobalt on WC substrates is approximately 54.65 kJ/mol.