Tribological Properties of Plasma Sprayed Chromium Carbide-Nickel Chromium Coating

Chromium carbide-nickel chromium coating has been found to be one of the most promising materials for wear resistance in automobile and aircraft engine with high rate of work and efficiency.In order to extend the application fields of the coating and give a theoretical bases for its applications,the sliding friction coefficients and wear mass losses of plasma sprayed chromium carbide-nickel chromium coating against stainless steel,hot-pressing sintered Si 3N 4,graphite were measured using a MM-200 wear tester.The morphology,element distribution and phase structure of worn tracks and debris of counterpart materials were examined employing the SEM,EDAX and XRD respectively.The wear behavior and wear mechanism of the coating against the three materials were discussed.The results obtained showed that the wear mass losses of the coating against the three materials change apparently.The wear of the coating against stainless steel is explained in term of spalling and fracturing.The wear of the coating against Si 3N 4 is due to the particles fractere of the coating and the decarbonization and oxidation of the fractured particles.Graphite,however,acts as a solid lubricant and improves the wear resistance of the coating.