The Effects of Composition on Solid State Sintering of Tungsten-Brass Composites

摘要

In this study, the effect of composition on solid state sintering of tungsten-brass was carried out. The densification of W-Cu has been a difficult problem to the materials engineers. However, the densification behaviour of tungsten-brass in the solid and liquid state is still not known. Tungsten-brass with the composition of 50W-brass, 60W-brass, 70W-brass and 80W-brass were sintered in a horizontal tube furnace under pure hydrogen environment at the temperature of 900°C and the relative sintered density, hardness, electrical conductivity and microstructural characterization was carried out. The relative sintered density and the electrical conductivity increase with the increase in the volume fraction of the matrix (brass) while the hardness decreases with the increase in the volume fraction of brass. The sample with the lowest volume fraction of W has the highest relative sintered density (71%) while the one with the highest volume fraction of W has the lowest relative sintered density (66%). The microstructure of the samples was not homogeneous due to mutual immiscibility between W and brass and lack of capillary force to enhance rearrangement and distribution of W and brass. It is obvious from the results that solid state sintering cannot give full densification of tungsten-brass composites.