A transformation-induced plasticity phenomenon in Fe₆₅(CoCrMnNi)₃₅ medium-entropy alloy was investigated. According to the X-ray diffraction patterns, the as-cast specimen contains a single-phase face-centered cubic (fcc), while low-temperature annealing at 500 °C and 600 °C leads to the introduction of a body-centered cubic (bcc) phase as a secondary phase. Further increment of the annealing temperature to above 700 °C eliminates the bcc phase, and the microstructure was found to contain a single-phase fcc. At 20% true strain, an fcc-to-bcc phase transformation is observed; whereas, at 28% true strain, an fcc-to-hcp phase transformation takes place as an additional deformation mechanism. This strain-induced phase transformation phenomenon leads to improved tensile properties of this alloy.

中文翻译：

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揭示中熵合金中的相变诱导可塑性（TRIP）现象

Fe ₆₅（CoCrMnNi）_35中的相变诱发塑性现象研究了中熵合金。根据X射线衍射图，铸态试样包含单相面心立方（fcc），而在500°C和600°C的低温退火导致引入了体心立方（bcc）阶段作为第二阶段。退火温度进一步升高至700°C以上可消除bcc相，并且发现微结构包含单相fcc。在真实应变为20％的情况下，观察到从fcc到bcc的相变。相反，在28％的真实应变下，从fcc到hcp的相变会作为附加的变形机制发生。这种应变引起的相变现象导致该合金的拉伸性能提高。