Microstructure, mechanical and elevated temperature tribological behaviors of the diamond/Cu composites prepared by spark plasma sintering method

摘要

Compact diamond/Cu composites with different contents of diamond particles were successfully prepared by the spark plasma sintering method. The tribological properties at elevated temperature of the diamond/Cu composites were studied. Results show that the addition of diamond particles in the Cu matrix could slightly increase the mechanical properties. Hardness and elastic modulus of the diamond/Cu composite with 50 vol% diamond particles reach about 31 GPa and 216 GPa, respectively, which are obviously higher than those of unreinforced copper alloy. The composite with 50 vol% diamond particles exhibits the lowest friction coefficient of 0.133 and lowest wear rate of 2.1-2.7 x 10(-6) mm(3)/Nm at 500 degrees C. The low friction coefficient of the composite is attributed to the copper debris which can react with moisture to form copper oxide, serving as the lubricant between the contact counterparts.