Codeposition of a-alumina particles from acid copper sulfate bath

The purpose of this work is to elucidate the factors affecting the codeposition of a-alumina particles with copper from an acid copper sulfate bath. The effect of current density and particle concentration in the bath on the amount of codeposited a-alumina were determined. In order to evaluate the surface-chemical properties of the particles, the zeta-potential of a-alumina particles in the plating bath was determined by means of the streaming potential method. The amounts of adsorbed Cu 2+ and SO2( from the plating bath were also determined. The amount of codeposited a-alumina particles was found to be greater than those reported in literature, in spite of the negative zeta-potential values of a-alumina. This indicates that the electrostatic interaction between the particles and the cathode is not the essential factor of the codeposition process. It is considered that the amount of adsorbed Cu 2+ on the a-alumina particle plays an important role in the codeposition behavior.