In this study, we present the first comprehensive examination of symmetry breaking in the interactions between dislocation and superlattice planar faults, including anti-phase boundary (APB), complex stacking fault (CSF), superlattice intrinsic stacking fault (SISF), to reveal the underlying asymmetric dislocation reaction mechanisms depending on the sense of applied stress, employing both large-scale atomistic simulations and continuum dislocation theory. Four ordered intermetallic alloy systems including and , , and were selected as the representative model systems, with two primary symmetry breaking effects, i.e., translational and three-fold rotational symmetry breaking considered. Detailed atomic steps of asymmetrical dislocation reactions and the corresponding asymmetrical dislocation bypassing mechanisms of precipitation have been elucidated, shown to be highly dependent on the geometrical configuration of the precipitate and the relative magnitudes of APB, CSF and SISF fault energies. A continuum model framework was then developed, which, for the first time, provides accurate and quantitative predictions of the threshold conditions triggering critical asymmetric dislocation slips, verified to be in good agreement with the simulation results. Our study also successfully reproduced the experimentally observed dislocation-induced APB-SISF transformation, with a new dislocation reaction mechanism proposed to explain the transformation process. The findings are expected to be a key enabling stepstone for future innovation in intermetallic alloys strengthened through ordered phases for advanced applications in aeronautic and automotive industries.

中文翻译：

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有序金属间合金中对称破缺诱导的不对称位错-平面断层相互作用

在这项研究中，我们首次全面检查了位错和超晶格平面断层之间相互作用的对称性破缺，包括反相边界（APB）、复杂堆垛层错（CSF）、超晶格本征堆垛层错（SISF），以揭示采用大规模原子模拟和连续体位错理论，根据施加应力的感觉，研究潜在的不对称位错反应机制。选择 和 、 、 和 四种有序金属间合金体系作为代表模型体系，考虑了两种主要的对称性破缺效应，即平动对称性破缺和三重旋转对称性破缺效应。不对称位错反应的详细原子步骤和相应的不对称位错绕过沉淀机制已被阐明，表明高度依赖于沉淀的几何构型以及 APB、CSF 和 SISF 断层能的相对大小。随后开发了连续体模型框架，该框架首次提供了触发临界不对称位错滑移的阈值条件的准确定量预测，并经验证与模拟结果非常一致。我们的研究还成功地重现了实验观察到的位错诱导的 APB-SISF 转变，并提出了一种新的位错反应机制来解释转变过程。这些发现预计将成为通过有序阶段强化金属间合金未来创新的关键基石，以用于航空和汽车行业的先进应用。