The response of a new tungsten-nickel-antimony alloy under low and high strain rates

The dynamic response of low sintering temperature tungsten-nickel-antimony alloys was investigated under low and high strain rates. For this purpose, W-7.6Ni-2.4Sb, W-6.8Ni-3.2Sb, and W-6Ni-4Sb alloys were first isostatically pressed and then sintered in a furnace under hydrogen atmosphere at 1300°C for 60 minutes. Mechanical properties were evaluated using a tension-compression apparatus and split Hopkinson pressure bar. In addition, microstructure of these alloys was analyzed using optical and scanning electron microscopes. The microstructure of all three alloys were contained of round tungsten particles in the metal matrix phase. The amount of the matrix phase in the alloy containing 3.2 % by weight of antimony was about 19.01 %. The alloy with 2.4 wt.% antimony had a compressive yield strength (1937 MPa) that exceeded that of two other alloys at high strain rate (2700 S−1). Adiabatic shear bands were detected in two alloys with a lower percentage of antimony (2.4 and 3.2 wt.% Sb). The width of these bands was about 20 µm. No shear bands were formed in alloy with 4 wt.% Sb. The sensitivity of strain rate in tungsten-nickel-antimony alloys was lower than tungsten-nickel-iron alloys. Replacing iron with antimony in tungsten heavy alloys improved the mechanical properties at high and low strain rates.