Effect of copper content on the dynamic compressive properties of fine-grained tungsten copper alloys

Experiments were conducted to evaluate the effect of Cu contents on the microstructures and dynamic compressive properties of three kinds of fine-grained tungsten copper (W-Cu) alloys with Cu contents in the range of 20–40 wt% prepared by isostatic cold pressing and infiltration. With the Cu content decreases from 40% to 20%, W grains grow slightly together with the W-W contiguity increasing and the homogeneity of microstructure improving. The dynamic yield strengths show an obvious increased tendency from 320 MPa in 60W-40Cu alloy to 1100 MPa in 80W-20Cu alloy. The yield strengths of the alloys show obvious strain rate strengthening effect. The three fine-grained W-Cu alloys exhibit good plasticity under compression with the dynamic critical failure strains of 0.6–0.85. The fracture mechanism is dependent on Cu content. The main failure modes are tearing of Cu phase, separation of W-W boundaries along with tearing of Cu phase, and failure of W shearing bands in 60W-40Cu, 70W-30Cu and 80W-20Cu alloys, respectively.