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

摘要

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.

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