Effect of heat treatment on physical properties of tungsten coating obtained by pulse electrodeposition

Abstract

Tungsten coated CuCrZr alloy with high thermal and electrical conductivity is a candidate for plasma facing components due to its high threshold energy for physical sputtering and favourable thermo-mechanical properties. The properties of over-aged CuCrZr alloy could be improved by annealing treatment. It is essential to investigate the effects of heat treatment on the properties of the tungsten coating. After annealed at 703 K for 12 h, and then air cooled out of the furnace, there is no significant changes on the preferred orientation and microstructure of the tungsten coating. Although the heat treated tungsten coating exhibited a tensile surface stress, the bonding strength between W coating and CuCrZr substrate was also near 60 MPa. Compared to the coatings prepared by plasma spraying, the heat-treated tungsten coating maintained a high the thermal conductivity which was measured to be about 149 W m−1 K−1.