Effects of Zn additions on the solid-state sintering of W–Cu composites

Full-density W–40 vol%Cu composites are prepared by hot-press sintering in a vacuum at 850 °C, as Zn is added as activator. Experiments are conducted to evaluate the effects of Zn additive in the range of 0–20 wt.% on the densification and mechanical properties of W–40 vol%Cu composites. The microstructural characterizations are performed by X-ray diffraction (XRD) and scanning electron microstructure (SEM), and mechanical properties such as Vickers hardness and bending strength are measured, respectively. The relative density increases gradually with increasing of Zn and it achieves 97.9% with a density of 14.53 g cm−3 at 2.0% Zn. As Zn increases, Vickers hardness increases at the beginning, and then keeps at certain level, finally increases again, the bending strength reaches the maximal value of 960.0 MPa at 14.0%. The results indicate that the sintering temperature is significantly lower with the usage of Zn.

► The relative density reaches 97.9% with an addition of Zn at 2.0%.
► There is the formation of solid solution between Cu and Zn.
► The Vickers hardness is increased.
► The bending strength achieves the maximum values 960.0 MPa.