Metastable dual-phase high-entropy alloys (HEAs) have become an attractive paradigm as structural materials due to their outstanding mechanical properties compared with single-phase HEAs, which originate from the multiple strengthening mechanisms. Herein, a theoretical model is established by integrating the effects of lattice distortion, dislocation, grain boundary, and phase transformation, to study the mechanical responses of metastable HEAs during uniaxial tensile deformation. The results show the contribution of various mechanisms to the strength, and strain hardening can be determined quantitatively. In particular, the face-centered cubic (FCC) to body-centered cubic (BCC) phase transformation would dominate the flow stress with plastic strain to exceed 6%, due to the strong phase interface strengthening and the formation of hard BCC phase. This work provides a microstructure-based constitutive model for predicting the flow stress and strain hardening properties of metastable HEAs.

中文翻译：

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亚稳态高熵合金屈服和应变硬化的建模与分析

亚稳态双相高熵合金 (HEAs) 与源自多重强化机制的单相高熵合金相比，由于其优异的机械性能，已成为一种有吸引力的结构材料范式。在此，通过整合晶格畸变、位错、晶界和相变的影响，建立了理论模型，以研究亚稳态 HEAs 在单轴拉伸变形过程中的力学响应。结果显示了各种机制对强度的贡献，并且可以定量确定应变硬化。特别是，由于强相界面强化和硬 BCC 相的形成，面心立方 (FCC) 到体心立方 (BCC) 相变将主导流动应力，塑性应变超过 6%。