In this study, quasi-static tensile properties of Fe₆₀Co₁₅Ni₁₅Cr₁₀ (at%) ferrous medium-entropy alloy at 298 K and 77 K were investigated in terms of thermally-activated deformation mechanism. Relatively high strain rate sensitivity and low activation volume were estimated using strain rate jump tests at 77 K where deformation-induced martensitic transformation took place, compared to those at 298 K. Different rate-controlling mechanisms were identified for early and latter deformation at both temperatures considering the plastic strain. Dislocation behaviors, e.g., cross-slip or dislocation accumulation, based on the thermally-activated deformation mechanism, support the outstanding cryogenic tensile properties of the present alloy.

在这项研究中，从热活化变形机理的角度研究了Fe ₆₀ Co ₁₅ Ni ₁₅ Cr ₁₀（at％）铁中熵合金在298 K和77 K时的准静态拉伸性能。与在298 K时相比，使用发生变形引起的马氏体相变的77 K处的应变率跳跃测试估计了相对较高的应变率敏感性和较低的激活量。对于两种温度下的早期和后期变形，都确定了不同的速率控制机制考虑塑性应变。基于热活化变形机理的位错行为，例如，横向滑动或位错积累，支持了本合金的出色的低温拉伸性能。