Microstructure, hardness and electrical properties of silver-based refractory contact materials

The electrical conductivity, hardness and microstructure of Ag-W and Ag-WC refractory contact materials have been investigated. Ag-W composites containing 30, 35, 45 and 85 wt.% of silver and Ag-40 wt.% WC composite produced by powder metallurgy were used for this investigation. The effect of graphite addition on hardness and electrical conductivity of Ag-WC composite was also evaluated. The present results show that the electrical conductivity of Ag-W composite increased with increasing Ag content, but decreased its hardness. The addition of WC to Ag increased its hardness, but decreased its electrical conductivity as compared with the addition of W to Ag. The addition of 3 wt.% C to Ag-37 wt.% WC composite decreased both its hardness and electrical conductivity. (C) 2003 Elsevier Science Ltd. All rights reserved.