Effect of surface roughness on tribological properties of TiB_2/Al composites

摘要

55 vol.% TiB_2/2024Al composites were fabricated by pressure infiltration method. The effect of surface roughness of GCrl5 steel disc (Ra 0.606,0.372,0.023,0.005μ.m) on the tribological properties of composites was investigated. Results showed that with the change of surface roughness, there is an optimal value (Ra 0.023 urn) under which the friction coefficient and wear rate is the lowest. The optimal surface roughness is in the same order of mixture of Ti_2 and B_2O_3, observed on the surface of TiB_2 particles after preheating process. During sliding, the filling of this oxidation layer into the asperity gap of GCrl 5 and greatly reduces adhesion between aluminium and GCrl 5, furthermore, decreases the friction coefficient and wear rate.