Thermal stress analysis on chemical vapor deposition tungsten coating as plasma facing material for EAST

Chemical vapor deposition-tungsten (CVD-W) coating on CuCrZr surface forming a flat-type structure is likely to be used as the vacuum wall materials except the divertor areas in EAST during its up-grade phase. This paper describes the residual thermal stress distribution in CVD-W coating substrate system using finite element analysis method (ANSYS code). Especially, the influence of interlayers, i.e. oxygen-free Cu (OFC) and W/Cu functionally gradient materials (FGMs) interlayer have been investigated in view of stress alleviation. Both the OFC and W/Cu FGMs interlayer can reduce the residual thermal stress, in which the OFC shows better interface and surface stress distribution than W/Cu FGMs, and is a preferred interlayer for CVD-W coating processing.