Effect of plasma source ion implantation on the mechanical properties of the trivalent chrome layer

Summary form only given, as follows. Summary form only given. Hard chromium electroplating had contributed much to industry over 50 years before the environmental problem of hexavalent chrome has arisen. Many researches related with hexavalent chromium replacement have been conducted according to extension of awareness about such an environmental problem. Among these studies, an investigation has been undertaken by nitrogen plasma ion implantation and pulsed plasma process to develop the novel process as an alternative to hexavalent chromium electroplating. In this study, Cr plating from trivalency chrome bath was conducted, followed by the plasma ion implantation (PIII) treatment to improve mechanical properties of the trivalency chrome plated films. Nitrogen ion implantation was conducted onto a Cr plating layer under the conditions of several implantation doses and implantation energies. The films were characterized by optical microscopy, RBS and nanoindentator. From the results, color of film surface after ion implantation was changed to gray, and number of cracks in the trivalency chrome plated layer increased. XRD analysis of the films indicated the formation of hard compound layer of chromium-nitride. The surface hardness was improved from 13 to 17 GPa and projected range (implantation depth) of nitrogen ions in the film was 30 nm. The detailed results will be presented.