Effect of blue tungsten oxide on skeleton sintering and infiltration of W-Cu composites

A novel W-skeleton sintering process was introduced by adding blue tungsten oxide (BTO). The effect of BTO on skeleton sintering and infiltration of W-Cu composites was investigated. The microstructural study, analyses of thermal diffusivity, as well as copper- and oxygen concentration of W-Cu composites were carried out using a combination of scanning electron microscopy (SEM), laser flash method and chemical composition analysis respectively. The results indicate that the addition of BTO can increase the porosity of the W-skeleton. As a consequence, copper concentration can be increased in W-Cu composites. The other beneficial effect is the formation of an open pore structure with the addition of BTO. The relative density is higher than 99% for W-25Cu composites with the addition of BTO and the corresponding theoretical thermal conductivity is 231 W/(m K). Furthermore, the BTO addition does not result in any increase of oxygen content of the W-skeleton.