Characterization of diamond-dispersed Cu-matrix composite

Dispersion of diamond in metal matrices is expected to improve friction and wear properties. In this paper, cluster diamonds (average grain size: 5nm) are dispersed in pure copper matrix by a P/M method. A mechanical milling method is employed for the composite powder mixing. First, the change in morphology after milling and sintering is observed by SEM. Next, the influence of milling time and cluster diamond content on the friction coefficient and the specific wear rate of the composite are examined, The friction coefficient measured by a ring-on-disk method decreases with the increase in both milling time and diamond content. About 30% reduction of friction coefficient compared with the pure copper is achieved for the composite (diamond content: 1 vol%) after a milling time of 40 hours. The specific wear rate also decreases with the milling time, However, the rate increases significantly as the diamond content increases. The experimental results show the possibility of a solid lublicant of diamond-dispersed metal matrix composites.