Temperature difference-induced surface tension gradients enable high densification of W-30Cu composites via ultrafast high-temperature sintering

The fabrication of highly dense W-Cu composites using conventional powder metallurgy techniques remains challenging, due to the significant differences in physical properties between tungsten and copper. In this study, micron-sized tungsten powder and spherical copper powder were selected as raw materials to prepare W-30Cu composite powders. Sintering was performed using the ultra-fast sintering (UHS) technique at temperatures ranging from 1050 °C to 1200 °C with holding times of 1, 3, 5, and 10 min. The results reveal that the sample sintered at 1150 °C for 10 min exhibited the highest relative density of 95.4 % and thermal conductivity of 234.2 W m⁻¹ K⁻¹. During the UHS process, the steep thermal gradient induced a surface tension gradient, which promoted the redistribution of the copper liquid phase and the rearrangement of tungsten particles. Compared to conventional tube furnace sintering under uniform temperature fields, this approach significantly enhanced densification and performance within a much shorter time. These findings suggest that the application of UHS provides a promising pathway for the fabrication of advanced composite materials.