Preparation and thermal shock characterization of yttrium doped tungsten-potassium alloy

Novel tungsten-based W-K-Y alloys were sintered by spark plasma sintering (SPS) method using fine-grained yttrium doped tungsten-potassium (W-K) powder. The relative density, microstructure, hardness and the resistance to thermal shock damage of the sintered samples were characterized. With the enhanced Y doping, the grain size decreased and the hardness increased. Thermal shock test under 0.37 GW/m2 heat load showed that low yttrium doping (0.05 wt%, 0.1 wt% and 0.5 wt%) in W-K-Y alloys can improve the resistance to thermal shock damage comparing with traditional commercial W-K, while high yttrium doping (1 wt%) easily leads to crack formation. This study will provide helpful information to optimize the preparation of tungsten-based plasma facing materials through composite tuning.