High heat load properties of actively cooled tungsten/copper mock-ups by explosive joining

Two actively cooled mock-ups with 2 mm thick tungsten armor joined to chromium copper alloy by explosive welding were developed, tested and analyzed in ASIPP of China. The heat load limit of the mock-up is 7 MW/m2, and delamination was observed along the W/Cu interface. The mock-ups can withstand the maximum heat flux of 6 MW/m2. SEM investigations showed that some cracks and failures appeared in filler materials and at copper/filler interface, but intactness was found at tungsten/filler interface. Numerical simulations indicated that if the distance decreases between the vertex of channel and the interface, the mock-up had the better structure reliability due to the reduction of temperature and stress. Under 4 MW/m2 heat flux, the mock-up showed good heat transfer capabilities and high joint reliabilities. All these results demonstrate the explosive joining is also an alternative way to realize the W/Cu joint for the plasma facing components.