Optimization of Plasma-Sprayed Tungsten Coating on Copper with the Heterogeneous Compliant Layer for Fusion Application

Structure of 1-mm tungsten (W) coating on copper (Cu) with the different compliant layers was designed and optimized by means of ANSYS code. Three materials of titanium, nickel-chromium-aluminum alloys, and W/Cu mixtures with a thickness of 0.5 mm were selected as the compliant layers to evaluate their effects on the interface stress between W and Cu, strain, and the surface temperature under the heat load of 5 MW/m 2 . Application of the compliant layers can obviously alleviate the interface stress concentration compared to the sharp interface. The maximum stress reduction of about 25% was obtained from the W/Cu-compliant layer; however, the surface temperature was increased only by 12 °C. Further investigation on the W/Cu-compliant layer revealed that 0.1-0.2-mm 20-35 vol.% W was the optimum structure for 1-mm W coating, which resulted in the smallest peak stress of 299 MPa and the equivalent plastic strain of 0.01%.