Microstructure and properties of WCu composites with low copper content at different sintering temperatures

For the tungsten‑copper composite salt solution prepared using the wet chemical method, micron-sized W-10/15wt.%Cu precursors with hollow spherical shell shape were prepared by spray drying. They were then subjected to hydrogen reduction to obtain irregularly shaped nanoscale W-10/15wt.%Cu composite powders, which were pressed under cold isostatic pressure to obtain high-density green bodies without forming agent and lower pressing force. Different densification processes were carried out at different sintering temperatures, thus remarkably influencing the microstructure and properties of WCu composites. At sintering temperature of 1350 °C, W-10/15wt.%Cu composites reached the maximum relative densities of 97.5 and 98.2 g/cm3, respectively, and exhibited the best thermal and mechanical properties. W-10wt.%Cu composites had a high thermal conductivity (TC) of 195 W/(m·K), coefficient of thermal expansion (CTE) of 6.20 ppm/°C, hardness of 346 HV, and flexural strength of 1146 MPa. W-15wt.%Cu composites also showed excellent performance with TC of up to 208 W/(m·K), CTE of 7.13 ppm/°C, hardness of 328 HV, and flexural strength of 806 MPa. The W-10/15wt.%Cu composites prepared in this study were of great application in the field of electronic packaging.