Wear Properties of High Speed Gold Electrodeposits

It had been observed that electrodeposits from acid goldplating solutions, when produced under production plating conditions, possessed variable wear characteristics. A laboratory study was undertaken to investigate the factors affecting the wear resistance of these gold deposits. The effect of plating parameters on wear resistance and deposit composition were examined to determine the optimum plating conditions for maximum wear resistance, and the relationship between wear resistance and codeposited elements. Three currently available proprietary electrolytes (two cobalt hardened, one nickel hardened) were compared and all deposits were produced at high current densities using high speed jet stream agitation. All the solutions tested produced deposits of acceptable wear resistance within specific "operating windows." These windows generally occurred at intermediate hardening element concentration and a potassium maximum, however, it has not been possible to define a specific cobalt (or nickel) and potassium content in the deposit which will guarantee wear resistance.