Irradiation hardening of WK-based PFM exposed to 14 MeV protons

W-based alloys are perceived as one of the most promising plasma-facing materials (PFMs). During the service of fusion reactors, W-based PFMs will be exposed to 14 MeV fusion neutrons, causing significant displacement damage and transmutation, consequently, the irradiation-induced defects will seriously deteriorate its service performance. The irradiation effect is always a critical issue in fusion reactors and concerns the performance and reliability of W-based PFMs. In this work, WK-0.05Ti alloy was irradiated under 14MeV protons, and notable irradiation hardening was observed using microhardness and nanoindentation characterization. Then, the mechanism of W-Re precipitate formation induced by K-bubble was revealed using transmission electron microscopy. Finally, the variation of hardness values at different irradiation depths was explained based on theoretical calculations and experimental data. The present work elucidates the effect of K-bubbles on the evolution of irradiation defects in WK-based PFMs during irradiation and reveals the underlying mechanisms contributing to the irradiation hardening at different depths. Moreover, it is expected to provide additional insights into the R&D of robust plasma facing components based on WK-based materials.