Behavior of actively cooled mock-ups with plasma sprayed tungsten coating under high heat flux conditions

High density tungsten is coated by vacuum plasma spraying technique (VPS) on tiles, 20 mm × 20 mm × 10 mm. Substrate materials are carbon/carbon composite (CX-2002U), isotropic fine-grained graphite (IG-430U). Thickness of the tungsten-coating layer is 0.5 mm. The tungsten-coated tiles are jointed by Ti brazing on the OFHC surface with a cooling tube. In addition, VPS-W coated TZM also has been brazed. Thermal response and thermal fatigue lifetime tests using an electron beam facility have been carried out on the tungsten coated mock-ups under the active cooling condition. Heat flux is changed from 1 to 10 MW/m2. The heat flux experiments have been carried out under the condition that the water flow velocity, pressure and temperature are 15.0 m/s, 0.5 MPa and 293 K, respectively. The use of high density VPS-W improves the performance of mock-ups under steady state heat flux condition. In addition, in the case of high density W coated CX-2002U on OFHC and W coated TZM on OFHC, it is demonstrated that the mock-up successfully withstood 100 cycles of heat loads at 10 MW/m2 at steady state.