Effect of load and sliding speed on friction and wear behavior of silver/h-BN containing Ni-base P/M composites

Sliding wear of behavior of Ni-based composites, prepared by powder metallurgy route and containing different (0, 8, 12, 16 and 20 wt.%) amounts of silver, was investigated under different loads and speeds by conducting wear tests against a counterface of AISI 52100 ring using a ring-on-disk set up. One composite containing 12 wt.% silver and 4 wt.% h-BN was also prepared and tested under same conditions to investigate the synergistic action of Ag and h-BN. The friction coefficients and the wear rates are significantly reduced by addition of silver and h-BN. The friction coefficient reduced from 0.36 to 0.21 by addition of solid lubricants whereas the reduction was 3-5 times in the wear rates. The friction coefficients of composites decreased with increasing load and sliding speed whereas the wear rates increased marginally. No noticeable synergy could be observed between silver and h-BN because h-BN fails to form strongly adherent transfer film on counterface surface. (C) 2010 Elsevier B.V. All rights reserved.