Fusion Science and Technology / Volume 56 / Number 2 / August 2009 / Pages 1053-1057
Fusion Materials / Eighteenth Topical Meeting on the Technology of Fusion Energy (Part 2)
Tungsten (W) coating on various low activation materials, such as ferritic steel (F82H), oxide dispersion strengthened (ODS) steel, and vanadium alloy NIFS-HEAT-2 (NH2) was successfully demonstrated by the vacuum plasma spray (VPS) process. Void and crack-type defects were observed in VPS-W. The mass density of VPS-W at room temperature (RT) was ∼90 % of the bulk W (sintered W). The thermal diffusivity and thermal conductivity of VPS-W from RT to 800 °C were 30∼50 % of the bulk W, while the linear expansion coefficient and specific heat of VPS-W were similar to the bulk W. The thermal conductivity of VPS-W was significantly lower than the bulk W, but was still larger than the NH2 substrate. There was no significant thermal contact resistance at the interface between W coating and NH2 substrate. Thus, the heat transfer properties of NH2 will not be degraded by the W coating with the VPS process.