金属玻璃是高温合金熔体深度过冷至玻璃态转变温度,其内部原子构型来不及有序结晶而形成的玻璃态固体。这类金属键的玻璃体系在原子排列上不存在长程周期性,在热力学上处于远离平衡的亚稳态,在动力学上处于阻塞态。这些特征赋予金属玻璃一系列优异的力学、物理、化学等性能,比如,具有接近理想极限的高强度。然而,金属玻璃的室温塑性变形极易局域化形成纳米尺度的剪切带,导致其宏观塑性十分有限。此外,自发的物理老化会使系统向低能量的平衡有序态转变,进一步削弱金属玻璃在服役过程中的塑性变形能力,表现出老化脆性。近年来,有研究表明,外部能量的输入能够使金属玻璃的结构发生"年轻化",从而达到在拓扑上更加无序的高焓状态。这一反物理老化过程能够有效改善金属玻璃的塑性变形能力,有望同时解决制约这类材料实际应用的剪切带和老化问题。因此,这方面的研究受到越来越多的关注。本文从玻璃的老化和年轻化概念出发,首先介绍了实现金属玻璃结构年轻化的主要方法,随后总结了影响年轻化的各种因素以及结构年轻化对金属玻璃塑性及其他力学行为的影响,并对金属玻璃结构年轻化的物理机制进行了评述。最后,对金属玻璃结构年轻化方面的研究进行了简要总结,并展望了该方面值得进一步研究的若干问题。

Metallic glasses (MGs) are formed by the deep undercooling of high-temperature melt up to the glass transition temperature, and this process avoids the crystallization of the melt into ordered configurations of atoms. The atomic packing of MGs lacks a long-range periodicity. MGs reside at metastable energy states far away from the equilibrium of thermodynamics, but they are jammed in dynamics. These features provide MGs with remarkable mechanical, physical, and chemical properties, such as very high strength that is close to the ideal limit. However, the plastic deformation of MGs at room temperature is easily localized to form nanoscale shear bands, thereby resulting in limited macroscopic plasticity. Moreover, physical ageing spontaneously reduces their energies toward an equilibrium state, thereby further weakening the plastic deformation ability of MGs, which is known as ageing-induced brittleness. Recent studies have shown that MGs can be rejuvenated with external energy injection into more disordered high-energy states in structure. This process, which is the inverse of physical ageing, can effectively improve the global plasticity of MGs and is expected to solve the problems of shear banding and physical ageing that restrict the applications of such materials. Therefore, the relevant aspects of the rejuvenation of MGs have attracted increasing interest. This article first introduces methods for the rejuvenation of MGs starting from the concepts of ageing and rejuvenation of glasses, and then summarizes the influencing factors of rejuvenation and the effects of rejuvenation on plasticity and other mechanical behaviors of MGs. Furthemore, the physical mechanism of rejuvenation is discussed briefly. Finally, several conclusions are drawn in this field, and some important problems that deserve further investigation are proposed.