Atomically informed nonlocal semi-discrete variational Peierls-Nabarro model for planar core dislocations

作者：Liu, Guisen; Cheng, Xi; Wang, Jian; Chen, Kaiguo; Shen, Yao^*

来源：Scientific Reports, 2017, 7(1): 43785.

DOI：10.1038/srep43785

• STACKING-FAULT ENERGY
• DENSITY-FUNCTIONAL THEORY
• CENTERED-CUBIC METALS
• SCREW DISLOCATIONS
• STRESS
• ALUMINUM
• CRYSTALS
• BARRIER
• EDGE
• FRAMEWORK

Prediction of Peierls stress associated with dislocation glide is of fundamental concern in understanding and designing the plasticity and mechanical properties of crystalline materials. Here, we develop a nonlocal semi-discrete variational Peierls-Nabarro (SVPN) model by incorporating the nonlocal atomic interactions into the semi-discrete variational Peierls framework. The nonlocal kernel is simplified by limiting the nonlocal atomic interaction in the nearest neighbor region, and the nonlocal coefficient is directly computed from the dislocation core structure. Our model is capable of accurately predicting the displacement profile, and the Peierls stress, of planar-extended core dislocations in face-centered cubic structures. Our model could be extended to study more complicated planar-extended core dislocations, such as <110> {111} dislocations in Al-based and Ti-based intermetallic compounds.

• 出版日期2017-3-2
• 单位上海交通大学; 中国工程物理研究院; 金属基复合材料国家重点实验室