Nanocrystalline W-Ta-Cr-V high entropy alloys have shown promising properties as nuclear fusion materials with enhanced radiation resistance to heavy ion irradiation and negligible radiation hardening. In this work, we investigate the performance of the alloy under low energy helium (He) implantation up to a fluence of 1.25 × 10¹⁷ cm⁻² at 1223 K. We observe a uniform high density of very small (~2–3 nm) bubbles grown at a slow rate along with enhanced He bubble damage resistance, further marked by no preferential bubble formation on the grain boundaries, even at much higher fluences compared to previously implanted tungsten grades. First principle calculations of He formation and migration energies in this alloy indicate deep energetic wells on the potential landscape and low diffusivity of He compared to pure W. The results imply higher overall (considering both grain matrices and grain boundaries) implantation resistance due to slow He diffusion and accumulation, and confirm the enhanced vacancy-self interstitial recombination argument in these alloys.

纳米晶W-Ta-Cr-V高熵合金已显示出令人鼓舞的性能，可作为具有增强的抗重离子辐射辐射能力和可忽略不计的辐射硬化能力的核聚变材料。在这项工作中，我们研究了低能量氦（He）注入至1.25×10 ¹⁷  cm ^-2的注量下合金的性能。在1223 K时。我们观察到均匀高密度的小气泡（〜2–3 nm）以缓慢的速度生长，并具有增强的He气泡破坏抗性，进一步的特征是在晶界上甚至在更高的晶界上都没有优先形成气泡与以前植入的钨等级相比，注量有所提高。该合金中He形成和迁移能的第一原理计算表明，与纯W相比，He的势能阱深，He的扩散率低。结果表明，缓慢的He导致更高的整体植入阻力（考虑晶格和晶界）扩散和积累，并证实了这些合金中空位-自组织间隙复合的增强。