Chemically activated liquid phase sintering of tungsten-copper

Liquid phase sintering of mixed W-Cu powders is hampered by the insolubility of tungsten in copper. In this study, the system properties were significantly improved by additions of less than 1w/o Co to the starting powder mixture. The effects of processing variables such as cobalt concentration, initial homogeneity, copper particle size, copper concentration, green density, heating rate, and sintering temperature were investigated. In response to these variables, density, strength, and microhardness were measured and related to microstructures, fracture surfaces, and grain sizes. The dependence of grain growth on activator concentration and sintering temperature is similar to that observed in the activated solid state sintering of tungsten with Co additions