Rare earth Ce-modified (Ti,Ce)/a-C:H carbon-based film on WC cemented carbide substrate**Project supported by the National Natural Science Foundation of China (Grant Nos. 51302116 and 51365016) and the Program for Excellent Young Talents, Jiangxi University of Science and Technology, China.

Abstract

WC cemented carbide suffers severe wear in water environments. A novel carbon-based film could be a feasible way to overcome this drawback. In this study, a rare earth Ce-modified (Ti,Ce)/a-C:H carbon-based film is successfully prepared on WC cemented carbide using a DC reactive magnetron sputtering process. The microstructure, mechanical properties, and tribological behavior of the as-prepared carbon-based film are systematically investigated. The results show that the doping Ti forms TiC nanocrystallites that are uniformly dispersed in the amorphous carbon matrix, whereas the doping Ce forms CeO2 that exists with the amorphous phase in the co-doped (Ti,Ce)/a-C:H carbon-based film. The mechanical properties of this (Ti,Ce)/a-C:H film exhibit remarkable improvements, which could suggest higher hardness and elastic modulus as well as better adhesive strength compared to solitary Ti-doped Ti/a-C:H film. In particular, the as-prepared (Ti,Ce)/a-C:H film presents a relatively low friction coefficient and wear rate in both ambient air and deionized water, indicating that (Ti,Ce)/a-C:H film could feasibly improve the tribological performance of WC cemented carbide in a water environment.