含共格纳米析出相高熵合金的辐照缺陷演化及抗辐照机理研究

高熵合金作为新型抗辐照结构材料受到广泛关注。当前，高熵合金的辐照损伤研究主要集中在具有简单结构的单相固溶体高熵合金，但其在剂量超过100dpa的高温辐照下肿胀严重，仍不足以适应第四代反应堆的高温和高剂量辐照环境，而通过引入缺陷“陷阱”来降低辐照缺陷浓度是进一步提升其抗辐照性能的关键。共格纳米析出相是具有良好热稳定性的缺陷陷阱，但其对高熵合金抗辐照性能的影响尚不清楚，亟需深入研究。因此，本项目以含共格纳米析出相高熵合金为主要研究对象，通过观测其在高温离子辐照下的缺陷演化规律，探索纳米尺度共格界面对高熵合金抗辐照性能的影响机制。同时，通过研究共格纳米析出相在高温辐照下的长大及消解等演化过程，探索高熵合金的“迟滞扩散”这一输运性质特征对缺陷陷阱辐照稳定性的影响。项目成果将揭示陷阱吸收与输运性质调控这两种抗辐照机制间的协同作用，为进一步提升高熵合金抗辐照性能提供新的设计思路和参考依据。

High entropy alloys are novel irradiation resistant structural materials, and have attracted significant attention. At present, the investigations of their irradiation behaviors have mainly focused on the single-phase solid solution alloys, however, these alloys experience severe void swelling under high fluence irradiation, and cannot meet the requirements by the Generation IV nuclear reactors. As an important type of defect trap with superior stability, coherent nanoprecipitates can absorb point defects produced by irradiation, which is key to further improving the irradiation resistance of high entropy alloys. However, the effects of coherent nanoprecipitates on the irradiation response of high entropy alloys remain unclear, and desire in-depth investigations. Therefore, this project will target on the high entropy alloys containing coherent nanoprecipitates, and characterize the irradiation-induced defect evolution under high temperature irradiation, in order to understand the impact of coherent nanointerface on the irradiation resistance of high entropy alloys. Moreover, this project will study the microstructure evolution of nanoprecipitates, in order to understand the effects of sluggish diffusion of high entropy alloys on the materials stability under high temperature irradiations. This project aims at unveiling the synergistic effects between defect trapping and transport property control, and eventually providing a new strategy of improving the irradiation resistance of high entropy alloys.