Effect of Tungsten Mesh, Short Fibers and Particles Reinforcements on Toughness of Reduced Activation High Entropy Alloy for Fusion Plasma Facing Applications

Tungsten (W) is a potential candidate for forthcoming fusion plasma facing applications due to its high melting temperature, high mechanical strength, low sputtering erosion and adequate thermal conductivity. However, tungsten accompanies some constraints including decrease in strength at temperatures above 1000 .deg. C, high ductile to brittle transition temperature and irradiation induced embrittlement. These limitations hinder the applications of W and persuade researchers to develop the innovative W-based materials for future fusion plasma facing applications. The researchers are developing novel W-based materials. However, the limitations of conventional alloys for instance poor workability, high energy in stimulating dislocation movement and weak passivation divert the research focus towards high entropy alloys (HEAs). The HEA offers high resistance to creep, fatigue and wear in addition to the high strength and hardness. In order to analyze the effect of W-based reinforcement (fiber) in W-matrix, the composite samples have been developed via hot isostatic pressing (HIP) and chemical vapor deposition (CVD). Although the reduction in brittleness of W-matrix has been observed due to ductile fracture of W-fibers, but premature ending of deposition of W-matrix in CVD resulted in low density of composite and secondary grain growth in HIP was observed.