Tunable interstitial and vacancy diffusivity by chemical ordering control in CrCoNi medium-entropy alloy  

作　　者：Yangen Li Jun-Ping Du Shuhei Shinzato Shigenobu Ogata 

机构地区：[1]Department of Mechanical Science and Bioengineering,Osaka University,Osaka 560-8531,Japan

出　　处：《npj Computational Materials》2024年第1期1898-1907,共10页计算材料学(英文)

基　　金：Y.L.,S.S.,and S.O.were used computational resources of supercomputer Fugaku provided by the RIKEN Center for Computational Science(Project IDs:hp230205 and hp230212);the large-scale computer systems at the Cybermedia Center,Osaka University,the Large-scale parallel computing server at the Center for Computational Materials Science,Institute for Materials Research,Tohoku University,and Research Center for Computational Science,Okazaki,Japan(Project:24-IMS-C503);S.S.and S.O.acknowledge the support by projects of MEXT of Japan(grant numbers JPMXP1122684766,JPMXP1020230325 and JPMXP1020230327);S.S.acknowledges the support by projects of JSPS KAKENHI(grant numbers JP21K14042,JP24K17170,and JP24H00994);S.O.acknowledges the support by projects of JSPS KAKENHI(grant numbers JP17H01238,JP21K18675,JP23H00161,and JP23K20037).

摘　　要：In this study,we utilized a quantitative atomistic analysis approach to investigate the impact of chemical ordering structures on the diffusion behavior of interstitials and vacancies within the CrCoNi medium entropy alloy(MEA),employing an advanced neural network interatomic potential(NNP).We discovered that the degree of chemical ordering,which can be precisely controlled through annealing at elevated temperatures,significantly influences both interstitial and vacancy diffusion.This phenomenon contributes to the notable sluggish diffusion characteristic of CrCoNi,largely attributable to the restriction of diffusion pathways in regions with lower degree of chemical ordering.We also emphasized the crucial role of operating temperature on diffusion,which should be remained well below the annealing temperature to preserve the sluggish diffusion effect.Our research sheds light on the interplay between chemical ordering and defect diffusion in MEAs,and it proposes effective strategies for tailoring the diffusivity of MEAs by altering their chemical ordering.These insights are instrumental in the development of next-generation materials,which are optimized for use in challenging environments,such as high-temperature and irradiation conditions.

关 键 词：ALLOY diffusion chemical 

分 类 号：TG1[金属学及工艺—金属学]