• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2026, Vol. 62 ›› Issue (4): 118-125.doi: 10.3901/JME.260110

• 材料科学与工程 • 上一篇    

扫码分享

迁移弯曲晶界与孔洞相互作用的分子动力学研究

刘晓晖1,2, 刘庆冬1,2   

  1. 1. 上海交通大学材料科学与工程学院 上海 200240;
    2. 上海交通大学材料改性与数值模拟研究所 上海 200240
  • 收稿日期:2025-02-13 修回日期:2025-08-30 发布日期:2026-04-02
  • 作者简介:刘晓晖(通信作者),男,1981年出生,博士。主要研究方向为材料力学性能多尺度分析。E-mail:liuxiaohui@sjtu.edu.cn
    刘庆冬,男,1982年出生,博士。主要研究方向为核燃料包壳用锆合金及腐蚀高性能合金钢的强韧性调控。E-mail:qdliu@sjtu.edu.cn
  • 基金资助:
    国家重点研发计划(2018YFA0702900)和中核集团领创科研基金资助项目。

Interaction Between Migrating Curved Gran Boundary and Void Via Molecular Dynamics Simulations

LIU Xiaohui1,2, LIU Qingdong1,2   

  1. 1. School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240;
    2. Institute of Materials Modification and Modeling, Shanghai Jiao Tong University, Shanghai 200240
  • Received:2025-02-13 Revised:2025-08-30 Published:2026-04-02

摘要: 近期研究表明,晶界能够溶解孔洞进而实现材料的自愈合。但目前报道仅限于平直晶界,尚缺乏对弯曲晶界与孔洞相互作用的研究。以面心立方结构金属Au为研究对象,对Σ5 36.87° <100>大角度倾转弯曲晶界在迁移过程中与孔洞的相互作用开展了分子动力学模拟。研究发现,在晶界与孔洞接触的初期,Gibbs-Thomson(GT)效应促使晶界快速压缩孔洞。后期,孔洞对晶界的拖拽效应有助于延长扩散时间,进而促进孔洞愈合。当孔洞足够小或温度足够高时,GT效应能够使弯曲晶界直接愈合孔洞。此外,弯曲晶界的曲率越小,迁移速度越慢,与孔洞相互作用的时间也越长,越有利于孔洞愈合。与曲率驱动迁移的弯曲晶界相比,在相同温度和迁移速度条件下,剪应力驱动迁移的平直晶界具有更强的愈合孔洞能力。

关键词: 弯曲晶界, 界面, 孔洞愈合, 扩散, 分子动力学模拟

Abstract: Recent studies have shown that voids can be dissolved by grain boundaries(GBs), thereby enabling self-healing of materials. However, they are largely limited to straight GBs, and the interaction between curved GBs and voids has not yet been reported. The interaction between voids and Σ5 36.87° <100> high-angle tilt curved GBs in an Au crystal during the GB migration is investigated by molecular dynamics simulations. It is found that in the initial stage of GB-void contact, the Gibbs-Thomson(GT) effect prompts the rapid compression of void by GB. In the later stage, the dragging effect of void on GB helps extend the diffusion time, thereby facilitating the void healing. When a void is sufficiently small or the temperature is sufficiently high, the GT effect enables the curved GB to directly heal the void. The smaller the curvature of the GB, the slower its migration, resulting in a longer interaction time with a void, which in turn favors void healing. Compared with a migrating curved GB driven by the curvature, a migrating straight GB driven by shear stress exhibits enhanced ability to heal voids with the same temperature and migration velocity.

Key words: curved grain boundary, interface, void healing, diffusion, molecular dynamics simulations

中图分类号: