Effect of plating time on surface evolution of chromium modified graphite powder by multi-arc ion plating

A novel and effective technology is proposed to prepare chromium modified graphite powder by the multi-arc ion plating process. Chromium modified graphite powder is held great promise in the interfacial modification of graphite reinforced metal matrix composites. In this study, chromium carbide is in situ generated and coated on the surface of chromium modified graphite powder. The chromium carbide coating exhibits the phase transformation evolution process of the surface at different plating time. The results indicate that the surface of graphite powder consists of dispersed H-Cr₇C₃ particles and chromium coating at 10 min plating time. With plating time increasing, plating ions supply sufficient energy and make chromium carbide coating generate phase transformation, the coating on the graphite surface is made of nano Cr₃C₂ particles and H-Cr₇C₃ coating at 30 min. When plating time up to 60 min, chromium carbide coating transforms into Cr₃C₂ coating and dispersed CrC particles.