Dual-phase high-entropy alloys (DP-HEAs) represent a paradigm shift in structural materials design, yet their unexplored deformation physics creates critical knowledge gaps hindering performance optimization. Here, we report the deformation behaviour and mechanical strengthening in the DP-HEAs with a variable Al content using crystal plasticity finite element (CPFE) method during the straining tests. The results show that the yield strength predicted by the hardening model aligns well with the existing experimental data. The body-centered cubic domains develop higher geometrically necessary dislocation density than face-centered cubic regions, acting as dynamic strengthening networks through phase boundary pinning effects. Stress concentration is notably pronounced at grain boundaries, particularly at phase boundaries, where significant stress, strain, and dislocation density gradients are observed. Furthermore, the activation of slip systems in the adjacent regions of different phases demonstrates a high degree of consistency. The proposed interface-mediated strain redistribution mechanism establishes new design rules for metastable HEA systems. This computational paradigm enables predictive optimization of phase-specific chemical ordering, providing a roadmap for developing HEA coatings in extreme mechanical environments.

中文翻译：

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结构化双相高熵合金的多尺度力学：位错-界面协同作用控制强度-延展性范式

双相高熵合金 （DP-HEA） 代表了结构材料设计的范式转变，但其未开发的变形物理学造成了阻碍性能优化的关键知识空白。在这里，我们报告了在应变测试期间使用晶体塑性有限元 （CPFE） 方法在可变 Al 含量的 DP-HEA 中的变形行为和机械强度。结果表明，硬化模型预测的屈服强度与现有实验数据吻合较好。与面心立方区域相比，体心立方区域产生更高的几何必要位错密度，通过相边界固定效应充当动态强化网络。应力集中在晶界处明显，尤其是在相界处，在那里观察到显著的应力、应变和位错密度梯度。此外，不同相的相邻区域中滑移系统的活化表现出高度的一致性。所提出的界面介导的菌株再分布机制为亚稳态 HEA 系统建立了新的设计规则。这种计算范式能够对相特异性化学排序进行预测优化，为在极端机械环境中开发 HEA 涂层提供了路线图。