To reduce the inhomogeneity from density difference in copper-graphite composite, which is a material system for DC-motor brushes, copper is deposited on graphite surface via electroless plating, and then the copper-plated graphite mixed with pure copper powders is pressed and sintered to produce a final compact. Here, we identified the optimum electroless plating condition for a large amount of copper deposition, and used it to prepare composite powders with pure copper. We compared the sintering behavior of the copper-plated graphite/copper composite powder with that of pure graphite/copper composite powder. The results show that the copper-plated graphite/copper composite significantly enhanced the sinterability of the composite powder, along with the homogeneity of the sintered compact.
Keywords: DC-motor brush, Electroless plating, Copper, Graphite, Sintering, Composites