Effect of W-coated diamond on the microstructure and thermal conductivity of diamond/W matrix composites for plasma-facing materials (PFMs)

摘要

Future fusion reactors need materials that can withstand high heat loads. This study introduced a production process of high thermal conductivity diamond/W composite materials via spark plasma sintering (SPS). The microstructures, structure of the interface, and thermal properties of the diamond/W composites are investigated. The results indicated that both the interfacial bonding and the thermal conductivity of the composite with a W coated layer are strengthened compared to the non-coated composites. The volume fraction of the diamond particles in the composites is between 10% and 50%. Moreover, thermal conductivity of 30% by volume of coated composites reaches 204 W/(mK), an increase of 18% over pure tungsten. A high thermal conductivity is achieved because of the formation of the diamond/WC, W2C/W structure at the interface between diamond and tungsten.