The kinetics of Ni-Co/SiC composite coatings electrodeposition

Ni-Co/SiC composite coatings with various contents of SiC particles were electrodeposited in a modified Watt's type of Ni-Co bath containing suspended 20 nm SiC particles. Deposition parameters including current density, bath SiC concentration and magnetic stirring rate were optimized for the highest amount of the SiC codeposition: the current density of 4A/dm(2), 40 g/dm(3) SiC concentration and 480 rpm stirring rate. In order to study the SiC particles codeposition, the Guglielmi's model of codeposition was modified for high volume percentages of the second phase and the modified model was employed to explain the effects of deposition parameters on the kinetics of the particles codeposition. Moreover, the influence of suspended SiC particles on the anomalous electrodeposition of Ni2+ and Co2+ ions was studied. In the presence of these particulates, anomalous electrodeposition of Ni2+ and Co2+ ions was enhanced. (C) 2010 Elsevier B.V. All rights reserved.