A Comparison of the Microstructure and Properties of Copper-Tungsten Composites Processed by Rapid Hot Pressing and Conventional Hot Pressing

摘要

The combination of copper with tungsten is of interest since it allows tailoring the thermophysical properties in a certain range. The thermal conductivity and the coefficient of thermal expansion can be varied by changing the ratio between the copper matrix and the tungsten filler. Depending on the material composition these composites are of interest for applications as heat sinks, electrical contacts or welding electrodes. Direct hot pressing was used to densify Cu-W composites with different concentrations of tungsten ranging from 20 wt.% to 80 wt.%. Compared to the conventional hot pressing technique, which is a rather slow process taking several hours, direct hot pressing allows the densification of these materials in less than one hour. Besides a comparison of the thermal conductivity/diffusivity and the coefficient of thermal expansion of the materials processed by the different consolidation methods the impact on the processing technique on the microstructure is shown and compared to commercial available products.