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

•A novel W-skeleton sintering process was introduced by adding BTO.•BTO is a potential addition to increase the porosity of the W-skeleton.•BTO is beneficial to the formation of an open pore structure.•W grain growth is obvious in the W-skeleton sintered with BTO.•The BTO addition does not result in any increase of oxygen content of the W-skeleton.

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.