Effects of temperature and holding time on bonding W and W–Cu composites with an amorphous W–Fe coated copper foil as the interlayer by hot-pressing

Abstract W and W–Cu composites were bonded with an amorphous W–Fe coated copper foil as the interlayer at different temperature and holding time by hot pressing method. Effects of the bonding temperature and holding time on the microstructure and thermal conductivity of the bonded specimens were investigated. The thermal conductivity of the bonded sample increased with the bonding temperature and reached the maximum at 1000 °C, but essentially unchanged with the holding time. Because at 1000 °C more W–Fe compounds would be formed at the interlayer, which were helpful for tight bonding of W and W–Cu composites, and the grain size was larger which could reduce thermal resistance. The W–Cu FGM bonded by this method showed good resistance to thermal load, and performed well when facing to short pulse plasma in experimental advanced superconducting tokamak (the first full superconductive fusion device in the world).