摘要
The capture efficiency describes the capability of a sink,such as a grain boundary(GB),dislocation,and void,to absorb point defects(PDs).The bias defines the difference in capture efficiency between the absorption of a vacancy and dumbbell at a sink.Complete kinetic information on PDs,including diffusion barriers and diffusion orientations,as well as accurate saddle points,are needed to determine the capture efficiency and bias at a sink accurately,which is computationally demanding.In the present study,the Self-Evolving Atomistic Kinetic Monte Carlo(SEAKMC)method was used to investigate the defect dynamics of PDs near different types of grain boundaries(GBs)(with both 100 and 110 families)accurately in body-centered cubic(BCC)iron(Fe).The capture efficiency,sink strength,and bias factor of different types of GBs were determined in Fe,which,different from traditional rate theory estimation,showed a distinct capture efficiency,sink strength,and bias in different GBs.The results demonstrate a strong positive correlation between the capture efficiency and the GB strain width,instead of the GB misorientation,GB energy,or GB-PD binding energy,which have been investigated previously.This work provides valuable insight into the radiation-induced microstructural evolution of GBs.
基金
the support by the National MCF Energy R&D Program with Grant No.2018YFE0308103
the National Natural Science Foundation of China with Grant No.51871007,12075023
the China Scholarship Council(CSC No.201706020125)
University of Tennessee Knoxville(UTK)Organized Research Unit(ORU)program
the support of the grant DE-SC0019151 funded by the U.S.Department of Energy,Office of Science。
