The influence of annealing temperature on the microstructural development of W–Cu composite powder prepared by high-energy ball milling

The microstructural characteristics of nanocrystalline W–Cu powder mixture were investigated as functions of annealing temperature. Open pores were observed after an annealing treatment at 300 °C, indicating that the pores that had entrapped as-milled powder opened. As the annealing temperature increased, the mean pore size increased and the pore size distribution broadened. The powder mixtures annealed above 500 °C showed significant differences in pore size distribution, powder density, and specific surface area. The changes in the powder characteristics were explained by Cu segregation and W grain growth due to the liquid-like behavior of Cu.