@article{Li2025, 
author = {Zikun Li and Chuanlong Xu and Xiaobao Tian and Wentao Jiang and Qingyuan Wang and Haidong Fan},
title = {Tension-compression asymmetry of pyramidal dislocations in magnesium},
year = {2025},
journal = {Journal of Magnesium and Alloys},
volume = {13},
number = {7},
pages = {3198-3208},
keywords = {Tension-compression asymmetry, Pyramidal dislocation, Magnesium, Molecular dynamics},
url = {https://www.sciopen.com/article/10.1016/j.jma.2024.07.010},
doi = {10.1016/j.jma.2024.07.010},
abstract = {Pyramidal dislocations are important for ductility enhancement of magnesium alloys. In this work, molecular dynamics simulations were employed to study the gliding behavior of pyramidal 〈c + a〉 dislocations under c-axis compressive loading and tensile loading. The Peierls stress of Py-Ⅰ dislocation shows strong tension-compression asymmetry. However, no tension-compression asymmetry is seen on the Py-Ⅱ dislocation and basal dislocation. The tension-compression asymmetry origins from the asymmetry of partial dislocations of Py-Ⅰ dislocation, which leads to the dislocation core contracted under c-axis compressive loading and expanded under tensile loading. By analyzing the forces acting on the partial dislocations, we defined a neutral direction, which deviates from the full dislocation Burgers vector by 70.3°. The neutral direction is dependent on the ratio of lattice stresses of partial dislocations. If the shear stress is applied along the neutral direction, tension-compression asymmetry is eliminated and the dislocation core is un-contracted/un-expanded. The neutral direction of symmetrical dislocations (Py-Ⅱ dislocation and basal dislocation) is just the full dislocation Burgers vector. The tension-compression asymmetry and dislocation core contraction/expansion have an important influence on the dislocation behaviors, such as cross-slip, decomposition, basal-transition and mobility, which can be used to explain the mechanical behaviors of Mg single-crystals compressed along c-axis.}
}