Mechanical and tribological properties of Ni-based alloy/CeF3/graphite high temperature self-lubricating composites

In this paper, Ni-based alloy/CeF3/graphite high temperature self-lubricati ng composites with different graphite addition amounts (0, 1, 3 and 5 wt.%) were prepared using P/M (powder metallurgy) method. Findings indicated tha t the addition of graphite could increase the compressive strength and hard ness of the composites, while poor results were obtained for the impact tou ghness at room temperature. The microstructures of the composites were stud ied using SEM with EDS and were correlated to their mechanical strengths wi th respect to the formation of carbides and graphite during the process. Th e effects of graphite addition amount on the friction and wear performances of the composites both at room temperature and 600 degreesC in air in slid ing against high speed steel (W18Cr4V) were investigated using a pin-on-dis k high temperature tribometer. Results showed that the wear rates of the co mposites and their counterparts could be remarkably reduced at room tempera ture with graphite addition. As for 600 degreesC, with no apparent improvem ent on wear resistance of the composites with graphite addition, the wear r ate of high speed steel was higher than that with no graphite addition. Fin ally, the wear rate of high speed steel at 600 degreesC was correlated to t he hardness of the composites and the wear mechanism was discussed. (C) 200 1 Published by Elsevier Science B.V.