Tribological performance of GLC, WC/GLC and TiN films on the carburized M50NiL steel

Abstract To improve the tribological performance of M50NiL aero-bearing steel, the TiN, GLC and WC/GLC films were deposited on the M50NiL steel treated by low pressure vacuum carburizing. GLC and WC/GLC films were prepared using unbalance magnetron sputtering system, and TiN films were deposited by magnetic filtered cathode vacuum arc system. The microstructures and mechanical properties of the films were evaluated. The tribological properties of the films were investigated in different environments including dry sliding and #4010 aviation lubricant. The results show that, in dry sliding, WC/GLC film exhibits better tribological performance than GLC film under the load ranging from 5 N to 15 N, while as the load increases to 20 N, the wear rate of WC/GLC film is about 10% higher than that of GLC film. In #4010 aviation lubricant, under the full load ranging from 5 N to 30 N, TiN film shows lower friction coefficient than GLC film, and WC/GLC film performs the best tribological performance. Moreover, the wear mechanisms of TiN, GLC and WC/GLC films were analyzed.