Processing of Sliding Hybrid Composites with Aluminum Alloy Matrix Containing Solid Lubricants

This paper presents the information about manufacturing processes of hybrid composites with aluminum alloy matrix containing glassy carbon as a solid lubricant. Two methods have been described: the method based on mixing glassy carbon and ceramic particles with a liquid metal matrix; and the precursor method. In the precursor method, carbon is introduced into a composite with the application of liquid precursor and porous ceramic foams. It is then followed by precursor pyrolysis where, as the result, glassy carbon is obtained. Ceramic foams help liquid precursor penetrate the ceramic spheroid pores by forming a thin film of glassy carbon on their walls. Composites produced by the both methods feature good tribological properties. Sliding friction coefficient in air of the new obtained by mixing method composite against cast iron (mu=0.08-0.17 at wearing in and 0.12 after wearing in by reciprocating sliding and 0.14-0.17 by rotating sliding) is much lower than in the case of composite containing only ceramic foam as a reinforcing phase (mu=0.28-0.36 by reciprocating sliding and 0.28-0.40 by rotating).