Impact response of a tungsten heavy alloy over 23-1100 °c temperature range

Impact response of a tungsten heavy alloy (WHA) prepared by liquid phase sintering of tungsten powder (∼80 vol. %) with an Ni-Co-Fe (3.50-1.25-1.0 weight ratio) binder was studied over a 23-1100 °C temperature range in a series of planar impact tests accompanied by continuous monitoring of the velocity of the WHA sample rear surface. The temperature dependence of the proof stress Y 0.1 (T) was found based on the 1D numerical simulations of the performed impact tests using a modified Steinberg-Cohran-Guinan constitutive model, and the temperature dependencies of the density ρ 0 (T) and longitudinal c l (T) and bulk c b (T) speeds of sound were found using rule of mixtures. The bulk speed of sound c b (T) was also used in determination of the temperature dependence of the spall strength σ s p (T) of the alloy based on the experimentally recorded velocity pull-backs Δ u p b. The strong decrease of both Y 0.1 (T) and σ s p (T) with temperature (Y 0.1 decreases almost sixfold between 23 and 1100 °C) allows one to assume that the tensile (spall) fracture of the alloy is controlled by the strength of its matrix.