报告题目：Recent progress of the research on concentrated solid solution alloys (CSAs) and high entropy alloys (HEAs) for nuclear application at Hokkaido Univ.
报 告 人：Naoyuki HASHIMOTO （橋本直幸）
报告时间：2020年8月14日下午1点-3点
报告地点：线上腾讯会议ID：576 069 497 密码Password ：0814
主办单位：开云Kaiyun
报告人简介：橋本直幸教授，博士毕业于日本北海道大学材料科学（金属材料）专业，随后在美国橡树岭国家实验室、田纳西大学从事核材料方向的研究，目前是日本北海道大学工学院材料科学系主任，兼任工学院国际合作办公室亚太区负责人；日本金属学会，日本原子力学会，日本显微镜学会，美国矿物金属材料学会（TMS），美国材料学会（MRS）会员。主要研究方向为聚变反应堆材料研究、辐照对材料微观结构的影响、辐照材料的微观结构/力学性能关系，辐照材料的变形机理、透射电子显微镜(TEM)。
报告摘要：
High Entropy Alloy (HEA) is an alloy in which multi-component elements are configured in almost equal ratios, unlike alloys in which a small amount of one or two elements is added to the main elements like conventional alloys. HEA is characterized by the random arrangement of atoms. Several HEAs form ductile solid solution structures involving face centered cubic (FCC) or body centered cubic (BCC) phases or mixtures of the two, instead of brittle intermetallic compounds. It has been reported that some HEAs have unique properties such as a high strength and high radiation resistance at elevated temperatures compared with conventional alloys. Those attractive physical and mechanical properties make HEAs potential candidates for high temperature fission or fusion structural applications. However, the studies on their radiation resistance at elevated temperatures relevant for potential nuclear energy applications is limited. It is hypothesized that the high mixing entropy of HEAs might influence point defect recombination in irradiated materials by modifying the distance of vacancy-interstitial recombination interaction, solute diffusivity, and other mechanisms, thereby producing different radiation stability compared to conventional single-phase alloys. Currently available austenitic stainless steels for light water reactors (LWRs) do not appear to exhibit sufficient radiation damage resistance for extended operation at elevated temperatures in next generation nuclear energy systems.
In this talk, we focus on the microstructural changes in electron- or ion-irradiated FCC-type HEAs and CSAs in order to better understand the mobility of the point defects and the effect of SFE on damage evolution under irradiation.
