Solid state sintering of a W-25 wt% Ag powder prepared by high energy milling

A composite W-25 wt% Ag powder was prepared by high energy milling (HEM). The mean particle size is 4.7 mu m, although agglomerates of composite particles around 50 mu m can be found. Neither phases were amorphized under the used milling conditions. Samples prepared with the composite powder and with a mixed powder were sintered in solid phase under the same conditions. The composite powder exhibited much higher sinterability, reaching 80% of relative density against 60% of the mixed powder. The composite powder also produces sintered structures with higher homogeneity. The high sinterability in solid phase of the composite powder is based on the sintering of a Ag layer that is formed on the surface of the composite particles by diffusion of Ag from the bulk. The layers build necks that sinter the structure. (C) 2007 Elsevier Ltd. All rights reserved.