Processing copper and silver matrix composites by electroless plating and hot pressing

A simple process was developed to fabricate ceramic-reinforced copper and silver matrix composites by electroless plating and hot pressing at 873 K and 300 MPa, in air. Composites were produced containing 10 to 40 vol pct ceramic reinforcements of different sizes and shapes including silicon carbide whiskers (SiCw), alumina particles (Al2O3p), carbon short fibers (Carbonsf), and Saffil short fibers (Saffilsf) (3.8 pct SiO2-96.2 pct Al2O3) uniformly distributed within the matrix. The hardness and bending strength of the composites were much higher than those of the pure matrices. The electrical conductivity, measured by a four-point probe method, was similar to that of traditional CdO/ Ag electrical contact materials. The surface morphologies and cross-sectional microstructures of the arc-eroded Al2O3p/Ag composites were similar to those of conventional CdO/Ag and SnO2/Ag and exhibited a good arc-erosion resistance. These composites combine the high strength and elevated-temperature stability of the ceramic reinforcements with the good electrical and thermal conductivity of the two metallic matrices.