Tribological properties of carbon-containing composite materials prepared by high-pressure high-temperature synthesis

The composite materials (CM) based on Co, Ti-Cu, and Pt and reinforced with diamond-like carbon particles and diamonds with different component ratios have been obtained by high-pressure high-temperature synthesis (5-9 GPa, 800-1800 degrees C). The methods of optical microscopy, dynamic indentation, and tribological tests were used to establish the correlation between the structure and properties of the reinforcing phase and CM and to define the limits of the applicability of the CM as tribotechnical materials. Low friction coefficients (0.08-0.06) were demonstrated by the CM reinforced with a superhard (35-40 GPa) diamond-like phase obtained from ball-milled fullerites with a cobalt binder as well as by the CM with diamonds regardless of the binder type and particle size. The wear resistance of the cobalt-based CM increases with increasing hardness of the reinforcing diamond-like particles. The condition for obtaining super wear-resistant CM from metal-fullerene mixtures is the synthesis at a temperature of about 800 degrees C, which ensures the collapse of fullerene molecules, but limits the graphitization of the diamond-like structure.