Physico-Mechanical Properties of the Cr-C and Mo-C Coatings

Abstract

The investigation of physico-mechanical properties of metal-carbon (Cr-C and Mo-C) coatings obtained using pulsed vacuum arc deposition has been carried out. Changing the arc discharge pulse repetition rate of the individual plasma sources equipped with metal and graphite cathodes allows significant varying of the composition, surface roughness and friction coefficient of the coatings. When reducing the pulse repetition rate in metal plasma source from 10 Hz to 5 Hz while retaining that constant in carbon source, the metal content in the coating can be decreased from 30 at.% to 2 at. % with increasing the surface roughness by a factor of 3.5. The tribological investigations of Cr-C and Mo-C coatings under the dry friction conditions showed the uniform adhesive wear of the coating upper layers. The coefficient of friction measured against steel counterbody was in the range of 0.08 to 0.1. However, in this case Mo-C coatings were more wear-resistant than Cr-C coatings.