Experimental results and theoretical concepts of anomalous phase transformations in alloys under severe plastic deformation (SPD) are reviewed. The unconventional phase and structural state of alloys that emerges as a result of SPD determines the unique combination of physical and chemical properties that is of interest for various applications in technology. The driving forces and possible mechanisms that implement the anomalous transformations as a function of SPD intensity, alloy composition, and temperature are discussed. We distinguish among these mechanisms two fundamental and qualitatively different ones that are due to: (i) direct ‘mixing’ of atoms in slip bands or (ii) accelerated diffusion on defects under locally alternating thermodynamic conditions and subsequent ‘freezing’ of the nonequilibrium state that is reached. Summarizing the experimental data and theoretical concepts regarding the change in microscopic transformation mechanisms as a function of temperature and/or intensity of treatment, we suggest a diagram of nonequilibrium stationary states attainable during the development of phase and structural instability under SPD. The proposed approach enables the prediction of the structural state of alloys and compounds by controlling thermodynamic and kinetic parameters of the system.

回顾了在严重塑性变形 (SPD) 下合金中异常相变的实验结果和理论概念。由于 SPD 而出现的合金的非常规相和结构状态决定了对各种技术应用感兴趣的物理和化学性质的独特组合。讨论了将异常转变作为 SPD 强度、合金成分和温度的函数来实现的驱动力和可能的机制。我们在这些机制中区分了两种基本的和性质不同的机制，它们是由于：（i）滑带中原子的直接“混合”或（ii）在局部交替热力学条件下缺陷的加速扩散和随后的非平衡状态“冻结”达到了。总结关于微观转变机制随温度和/或处理强度变化的实验数据和理论概念，我们提出了在 SPD 下相和结构不稳定性发展过程中可达到的非平衡稳态图。所提出的方法能够通过控制系统的热力学和动力学参数来预测合金和化合物的结构状态.