Stress analysis of divertor plasma-facing component designs using tungsten particle-reinforced copper composite heat sink

Abstract The W-Cu composites are considered as advanced heat sink material for plasma-facing components, depending notably on the reduced macroscopic coefficient of thermal expansion compared with monotonic Cu materials. One class of such W-Cu composite materials is W particle-reinforced Cu composites which can be joined to pure tungsten parts as plasma-facing armor. After heat flux tests with 20 MW/m2 and with a target of 500 cycles, it is found that fracture occurred after around 100 cycles either on the side of W-armor or on the interface between W-armor and W-Cu composite heat sink. In this work, the stress as well as temperature processes during the cyclic heat flux loadings have been investigated with finite-element method for two designs with W-Cu composite materials, and compared with the former design with W-armor and CuCrZr-heat sink. Possible causes for the fracture have been proposed.