Deep Insights into Complicated Superdislocation Dissociation and Core Properties of Dislocation in L1 2 ‐Al 3 RE Compounds: A Comprehensive First‐Principles Study

• Published in: physica status solidi (b) Vol. 259; no. 11
• Main Authors: Ma, Li, Huang, Jingli, Tang, Pingying, Huang, Guohua, Zeng, Li, Wang, Zhipeng, Fan, Touwen
• Format: Journal Article
• Language: English
• Published: 01.11.2022
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.202200211

The complicated superdislocation dissociation, dislocation core properties, and slip mechanism of L1 2 structural alloys have been controversial. Herein, the generalized stacking‐fault energy surfaces (γ‐surfaces) of the {001}, {110}, and {111} planes in L1 2 ‐Al 3 RE (RE = Er, Tm, Yb, Lu) compounds are first calculated according to ab initio density functional theory. Based on the γ‐surfaces, the superdislocation dissociation modes are preliminarily estimated using the unstable and stable stacking‐fault energies and their ratio. The result shows that the possible type of dissociations cannot be determined just from these ratios. Then, the 2D Peierls–Nabarro (PN) model is applied to simulate the ⟨110⟩{111} superdislocation dissociation configuration evolution in L1 2 ‐Al 3 RE, and the complete dislocation properties, including the dissociation width, the dislocation movement, and the Peierls energy and stress, are also investigated. The present study indicates that the combination of the γ‐surface and the 2D PN model can comprehensively elucidate the superdislocation properties and deformation mechanisms of L1 2 structural alloys.