Modeling the Interaction between Vacancies and Grain Boundaries during Ductile Fracture  

作　　者：Mingjian Li Ping Yang Pengyang Zhao 

机构地区：[1]Department of Engineering Mechanics,School of Naval Architecture,Ocean and Civil Engineering,Shanghai Jiao Tong University,Shanghai,200240,China

出　　处：《Computer Modeling in Engineering & Sciences》2024年第8期2019-2034,共16页工程与科学中的计算机建模（英文）

基　　金：supported by the National Key Research and Development Program of China under Grant No.2023YFB3712401;the National Natural Science Foundation of China under Grant Nos.12102254 and 12327802.

摘　　要：The experimental results in previous studies have indicated that during the ductile fracture of pure metals,vacancies aggregate and form voids at grain boundaries.However,the physical mechanism underlying this phenomenon remains not fully understood.This study derives the equilibrium distribution of vacancies analytically by following thermodynamics and the micromechanics of crystal defects.This derivation suggests that vacancies cluster in regions under hydrostatic compression to minimize the elastic strain energy.Subsequently,a finite element model is developed for examining more general scenarios of interaction between vacancies and grain boundaries.This model is first verified and validated through comparison with some available analytical solutions,demonstrating consistency between finite element simulation results and analytical solutions within a specified numerical accuracy.A systematic numerical study is then conducted to investigate the mechanism that might govern the micromechanical interaction between grain boundaries and the profuse vacancies typically generated during plastic deformation.The simulation results indicate that the reduction in total elastic strain energy can indeed drive vacancies toward grain boundaries,potentially facilitating void nucleation in ductile fracture.

关 键 词：Ductile fracture VACANCY grain boundary MICROMECHANICAL finite element method 

分 类 号：TG14[一般工业技术—材料科学与工程]