非晶合金由于其固有长程无序、短程有序的原子结构特征，在具备优异的力 学性能的同时，其室温下的塑性变形极易形成纳米级剪切带，最终一条或多条剪 切带快速扩展诱致材料的宏观脆性断裂，使非晶合金作为工程结构材料的应用受 到严重制约。相关的研究表明，非晶合金的室温宏观塑性可通过多种方法进行改 善，而认识其室温塑性与无序结构演化的关联机制，是改善其宏观塑性的关键。 为此，本文基于力调控方法围绕非晶合金塑性与无序结构关联演化机制这一关键 问题，以预约束压缩加载为切入点，从有限元模拟和实验两方面开展了研究。 通过有限元模拟研究了不同初始无序结构的非晶合金从弹性变形到屈服再 到剪切带形成的变形过程，发现了不同初始无序结构的非晶合金在变形过程中自 由体积统计分布呈现不同的演化模式，提出了自由体积浓度统计分布偏度作为非 晶合金中屈服和剪切带形成的无序结构表征参数。从原子层次上揭示了自由体积 浓度统计分布偏度的变化是由较高自由体积浓度和中间自由体积浓度之间的演 化作用竞争导致，进一步获得了非晶合金屈服和剪切带形成对初始无序结构的依 赖规律。 通过准静态预约束加载实验、有限元模拟研究了预约束压缩加载对非晶合金 宏观塑性的影响，揭示了样品在预约束压缩加载后呈现不同的塑性变形模式。在 预约束压缩加载应变很小时，非晶合金的宏观变形呈现脆性断裂；在预约束压缩 加载应变 5.0%附近时，非晶合金的宏观变形呈现韧性断裂，样品内部发生稳定 的塑性流动的同时，样品的强度实现同步提升；当预约束压缩加载应变 6.7%时， 观察到非晶合金的宏观塑性较应变 5.0%时略有下降，实现了对非晶合金宏观塑 性的连续调控，得到了非晶合金强度与塑性随预加载程度的变化规律。 通过原子力显微镜实验、有限元模拟研究了预约束压缩加载下非晶合金无序 结构演化规律，通过不同程度的预约束压缩加载，可以引入更多的自由体积或类 液相区，实现非晶合金的年轻化。通过有限元模拟揭示了预约束压缩加载后样品 在单轴压缩下的无序结构演化行为，通过自由体积浓度统计分布偏度建立了非晶 合金的无序结构和宏观塑性的内在关联。

Due to the inherent long-range disordered and short-range ordered atomic structure characteristics, metallic glasses possess excellent mechanical properties while the plastic deformation is easily to form nanoscale shear band at room temperature, and eventually one or more shear bands expand rapidly leading to macroscopic brittle fracture of the material, which severely limits the application of metallic glasses as engineering structural materials. Related studies have shown that macroscopic plasticity of metallic glasses at room temperature can be improved by various methods, and correlation mechanism between plasticity at room temperature and the evolution of disordered structure of the material is an important basis for improving its macroscopic plasticity. Therefore, this article carries out a series of studies through finite element simulations and experiments, focusing on the evolution mechanism of association between plasticity and disordered structure of metallic glasses based on force regulation method, taking the pre-constrained compression loading as the entry points. The evolution of metallic glasses with different initial disordered structures from elastic deformation to yielding to shear band formation is investigated by finite element simulation, and it is found that the free volume statistical distribution of metallic glasses with different initial disordered structures shows different evolution patterns during the deformation process. It is revealed at the atomic level that the variation of the skewness of the free volume concentration statistical distribution is caused by the evolutionary competition between higher and middle free volume concentrations, and the dependence of the yielding and shear band formation on the initial disordered structure of the metallic glasses is further obtained. The effects of pre-constrained compression loading on the macroscopic plasticity of metallic glasses were investigated by quasi-static pre-constrained loading experiments and finite element simulations, revealing that the samples showed different plastic deformation patterns after pre-constrained compression loading. The macroscopic deformation of the metallic glasses shows brittle fracture when the preconstrained compression loading strain is very small; when the pre-constrained compression loading strain is around 5.0%, the macroscopic deformation of the metallic glasses shows ductile fracture, and a stable plastic flow occurs inside the sample while the strength of the sample achieves simultaneous increase; when the pre-constrained compression loading strain is 6.7%, the macroscopic plasticity of metallic glasses is observed to be slightly lower than that at 5.0%, and the continuous regulation of the macroscopic plasticity of metallic glasses is achieved. The evolution law of disordered structure of metallic glasses under pre-constrained compression loading was studied by atomic force microscopy experiments and finite element simulations. More free volume or liquid-like phase regions can be introduced through different degrees of pre-constrained compression loading to achieve the rejuvenation of metallic glasses. The disordered structure evolution behavior of the sample under uniaxial compression after pre-constrained compression loading is revealed by finite element simulation, and the intrinsic correlation between the disordered structure and macroscopic plasticity of the metallic glasses is established by the skewness of the statistical distribution of the free volume.