Activated sintering and thermal properties of 1 wt. Ag-W/Cu thermal-management composites

摘要

W/Cu composites have received much attention for applications as in electronic packaging and heat sink materials. There exists difficulties in fabricating W/Cu composites due to the mutual insolubility of tungsten and copper. In this article, high density 1 wt. %Ag-W/Cu composites are prepared by sintering the mixed powders of copper-coated tungsten powders and silver-coated copper powders under different temperature. The densification and thermal conductivity of 1 wt. %Ag-W/Cu composites are studied under different sintering temperatures. The results show that the existence of Ag can promote low-temperature densification due to the formation of minor amount of Cu-Ag liquid-phase alloys. The relative density of 1 wt. %Ag-W/Cu composites can achieve 98.3% at 900°C. Thermal conductivity of 1 wt. %Ag-W/Cu composites can reach the maximum value of 234.1W/ (m.K) at 850°C. In this work, the high-purity copper network structure can obtained from highly pure copper-coated tungsten powders, and the excellent thermal conductivity of the composite is mainly due to Ag additives and high-purity copper network structure.