Enhanced helium ion irradiation tolerance in a Fe-Co-Ni-Cr-Al-Ti high-entropy alloy with L12 nanoparticles

作     者：Y.L.Zhao F.L.Meng T.Yang J.H.Luan S.F.Liu G.M.Yeli W.T.Lin W.H.Liu X.J.Liu C.T.Liu J.J.Kai Y.L.Zhao;F.L.Meng;T.Yang;J.H.Luan;S.F.Liu;G.M.Yeli;W.T.Lin;W.H.Liu;X.J.Liu;C.T.Liu;J.J.Kai

作者机构：School of Materials Science and EngineeringHarbin Institute of Technology(Shenzhen)Shenzhen 518055China School of Materials Science and EngineeringSouthern University of Science and TechnologyShenzhen 518055China Department of Materials Science and EngineeringMechanical Behavior Division of Shenyang National Laboratory for Materials ScienceCity University of Hong KongHong KongChina Department of Mechanical EngineeringCity University of Hong KongHong KongChina Institute of Nuclear&New Energy TechnologyTsinghua UniversityBeijing 100084China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2023年第143卷第12期

页      面：169-177页

核心收录：

学科分类：08[工学] 0806[工学-冶金工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：Harbin Institute of Technology (Shenzhen) thank the financial support from the National Natural Science Foundation of China 广东省深圳市项目 the City University of Hong Kong greatly acknowledge the financial support from the National Natural Science Foundation of China the Hong Kong Research Grant Council (RGC) the Guangdong Basic and Applied Basic Research Foundation 广东省深圳市项目 

主　　题：L12 nanoparticles High-entropy alloy Helium bubble Phase stability Radiation-induced segregation 

摘      要：L12-strengthened high entropy alloys(HEAs)with excellent room and high-temperature mechanical prop-erties have been proposed as promising candidates as structural materials for advanced nuclear systems.However,knowledge about their radiation response is fairly limited.In the present work,a novel HEA with a high density of L12 nanoparticles was irradiated with He ion at 500°C.Transmission electron microscope(TEM)and atom probe tomography(APT)were employed to study the evolution of mi-crostructural stability and radiation-induced segregation.Similar to the single-phase FeCoNiCr HEA,the main microstructural features were numerous large faulted dislocation loops and helium bubbles.While the irradiation resistance of the present L12-strengthened HEA is much improved in terms of reduced bubble size,which could be attributed to the considerable He trapping efficiency of the coherent pre-cipitate/matrix interface and the enhanced capability of the interface for damage elimination when the matrix channel width is narrow.APT analysis revealed that an inverse-Kirkendall-mechanism-dominated radiation-induced segregation(RIS)occurs around bubbles,where a significant Co enrichment and Ni de-pletion can be clearly observed.In addition,the competing dynamics of ballistic mixing and elemental clustering that raised from the irradiation-enhanced diffusion in a highly supersaturated matrix,along with the low precipitation nucleation barrier due to the small lattice misfit,lead to a dynamical pre-cipitation dissolution and re-precipitation appears under irradiation.Such a promising phenomenon is expected to promote a potential self-healing effect and could in turn provide a sustainable irradiation tolerance over the operational lifetime of a reactor.