Effect of sinter duration on the mechanical properties of a tungsten alloy

Abstract

The effect of sinter duration on the tensile strength and ductility in tension of a 95%W-3.5%Ni-1.5%Fe alloy was shown to be negligible. The alloy showed a broad ductile to brittle transition as the testing temperature was reduced below 100°C, and this was also unaffected by the sinter duration. Despite the negligible change in mechanical properties with sinter duration, the fracture mode changed with an increased proportion of transgranular tungsten grain fracture at the expense of tungsten-tungsten interface fracture, at the longer sintering times. Quantitative metallography showed that grain size increases and tungsten-tungsten spheroid interface area decreased with increasing sintering time. The mechanical property and fracture morphology observations have been interpreted in terms of these microstructural changes.