Microstructural Evolution and Mechanical Properties under High Strain Rate Testing of W–3.99Ni–1.71Fe Sintered by a Two-Stage Sintering Process

Abstract

A two-stage sintering practice was applied to W–3.99Ni–1.71Fe (mass%) to control its microstructural evolution and, accordingly, mechanical properties under high strain rates. Unlike the traditional one-stage liquid phase sintering, the alloy was first solid-state-sintered to close to full densification, and then liquid-phase-sintered by induction heating where the cooling rate was fast. With the two-stage sintering, the growth of tungsten grains and the contiguity of tungsten grains could be closely tailored, and a high dissolved tungsten concentration in the matrix phase could be maintained. All of these microstructural characteristics led to enhanced mechanical properties of this alloy tested under high strain rates.