Demonstrating tungsten fiber-reinforced porous-matrix tungsten composites for future fusion application

Tungsten fiber-reinforced tungsten (W f /W) has been developed to improve the fracture toughness of W materials, as demonstrated in previous studies (2019 Nucl . Fusion 59 086034; 2021 Mater . Sci . Eng . A 817 141361). In the present study, we focus on the performance of the developed W f /W materials under fusion-relevant test conditions and further demonstrate their use as plasma facing materials in future fusion reactors. Specifically, one set of W f /W samples was exposed to Ne plasma to investigate the erosion resistance against plasma sputtering, in comparison to the reference ITER-grade W sample. In addition, deuterium (D) retention in the plasma-exposed W f /W samples was studied via thermal desorption spectroscopy. Furthermore, laser thermal shock tests were performed on W f /W to simulate the transient heat load condition and to investigate the material performance under extreme heat flux. With increasing porosity, W f /W exhibits lower mass loss (net erosion) after Ne plasma exposure. Though porous, W f /W composites unexpectedly show a comparable D retention to the reference bulk W, which is attributed to the openness of the pores in the matrix. Thermal shock testing results indicate a similar cracking threshold (0.38 GW m −2 , 1 ms) as compared with that of ITER-grade W materials. However, due to the lower thermal conductivity of porous matrix W f /W, under extremely high loading conditions (1.6 GW m −2 , 2 ms) surface melting was observed. The present work demonstrates the great potential of the porous matrix W f /W for future fusion application.