Acta Metallurgica Sinica (English Letters) ›› 2010, Vol. 23 ›› Issue (5): 370-380.DOI: 10.11890/1006-7191-105-370

• 研究论文 • 上一篇    下一篇

原子模拟镁单晶拉伸变形行为

郭雅芳1,汪越胜2,亓洪刚2,Dirk STEGLICH2   

  1. 1. 北京交通大学
    2.
  • 收稿日期:2010-05-10 修回日期:2010-06-11 出版日期:2010-10-25 发布日期:2010-10-14
  • 通讯作者: 郭雅芳

Atomistic simulation of tension deformation behavior in magnesium single crystal

Yafang GUO1, Yuesheng WANG1, Honggang QI1, Dirk STEGLICH2,3   

  1. 1. Institute of Engineering Mechanics,Beijing Jiaotong University, Beijing 100044, China
    2. GKSS Research Centre, Institute of Materials Research, Materials Mechanics, D-21502 Geesthacht, Germany
    3. Graduate Institute of Ferrous Technology, Pohang University of Science and Technology, Pohang, Gyeongbuk, 790-784, Korea
  • Received:2010-05-10 Revised:2010-06-11 Online:2010-10-25 Published:2010-10-14
  • Contact: Yafang GUO

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摘要： 镁及镁合金是最轻的金属结构材料，广泛应用于航空航天工业、军工、交通等领域。由于镁及大部分镁合金均为密排六方晶体结构，滑移系少，相对于其它面心或体心结构金属来说塑性较差。本文运用分子动力学方法模拟了镁单晶在不同温度下沿c轴的拉伸时的变形机制。研究结果表明：在低温拉伸过程中，孪晶和剪切带是主要的变形行为。{10-12}孪晶是主要的拉伸形变孪晶，其与原始晶粒取向差约为90°，并通过原子运动的图像给出其形成机制。此外，模拟中还发现新晶粒形核伴随{10-12}孪晶的生长。当温度升高至450K以上时，孪晶的数量随着温度升高而减少。当温度达到570K时，{10-12}扩展孪晶几乎完全消失，非基面滑移成为高温拉伸的主要变形方式。

关键词: 原子模拟, 镁, 孪晶, 拉伸

Abstract: The deformation behavior in magnesium single crystal under c-axis tension is investigated in a temperature range between 250 K and 570 K by molecular dynamics simulations. At a low temperature, twinning and shear bands are found to be the main deformation mechanisms. In particular, the {1012} tension twins with the reorientation angle of about 90° are observed in the simulations. The mechanisms of {1012} twinning are illustrated by the simulated motion of atoms. Moreover, grain nucleation and growth are found to be accompanied with the {1012} twinning. At temperatures above 450 K, the twin frequency decreases with increasing temperature. The {1012} extension twin almost disappears at the temperature of 570 K. The non-basal slip plays an important role on the tensile deformation in magnesium single crystal at high temperatures.

Key words: Atomistic simulations, Magnesium, Twinning, c-axis tension