CHARACTERISTICS OF ELECTRO-CODEPOSITION OF COBALT-TITANIA COMPOSITES

The effect of bath parameters, such as concentration of the dispersoid, current density, pH, stirring rate, surfactant and chloride ion concentrations, on the codeposition of TiO2 with cobalt from a sulfate bath have been studied. The first three factors showed an optimum value for maximum codeposition, whereas the latter factors detrimentally influenced the codeposition. The crystal structure of the cobalt matrix also showed variations with current density and pH. The conventional electro-codeposition (CECD) method produced a very uniform and unagglomerated distribution of TiO2 in the matrix, unlike the sediment electro-codeposition (SECD) method. Guglielmi's model shows a reasonable fit with the CECD codeposition mechanism. A modified model, however, explains the mechanism better.