Preparation and properties of W–Cu–Zn alloy with low W–W contiguity

The W–Cu–Zn alloy with α-brass matrix and low W–W contiguity was prepared by method of electroless copper plating combined with spark plasma sintering (SPS) method. The effects of process and parameters on the microstructure and mechanical properties of the alloy were investigated. The W–Cu–Zn alloy with a relative density of 96 % and a W–W contiguity of about 10 % was prepared by original fine tungsten particles combined with wet mixing method and SPS solid-state sintering method at 800 °C for 10 min. The microstructure analysis shows that Cu–Zn matrix consists of nano-sized α-brass grains, and the main composition is Cu₃Zn electride. The nano-sized Cu was coated on the surface of tungsten particles by electroless copper plating method, and the fairly low consolidation temperature and short solid-state sintering time result in the nano-sized matrix phase. The dynamic compressive strength of the W–Cu–Zn alloy achieves to 1000 MPa, but the alloy shows poor ductility due to the formation of the hard and brittle Cu₃Zn electrides. The fine-grain strengthening and the solution strengthening of the Cu–Zn matrix phase are responsible for the high Vickers microhardness of about 300 MPa for W–Cu–Zn alloy.