Dynamic mechanical relaxation is an important metric to understand the mechanical/physical properties of amorphous solids which are of viscoelastic nature. Due to the heterogenous microstructure, the relaxation behavior of amorphous solids usually shows strong deviation from the Debye relaxation. The distribution of relaxation time derived from either the stretched exponential function (KWW function) or the power law form is probably the most adopted paradigm to describe the non-Debye relaxation. They are essentially the continuous spectrums given in analytical forms. However, whether a real amorphous material conforms to such distribution law remains to be discussed. Here we test the assumption in typical metallic glasses (MGs) as representatives of the general amorphous solids. The mechanical spectrum of a Cu₄₆Zr₄₇Al₇ MG in wide frequency domain is probed by the dynamic mechanical analysis technique. It is found that both the KWW function and the modified fractional (MF) model based on power law can well describe the experimental data. As a step forward, we combine the quasi-point defect theory with the MF model to theoretically reveal the feature of temperature-dependent structural evolution in MG. Finally, the distribution of relaxation time corresponding to the experimental data is discretized to argue the theoretically predicted microstructural heterogeneity in the MGs.

动态机械松弛是了解具有粘弹性的无定形固体的机械/物理性质的重要指标。由于微观结构的不均匀性，无定形固体的弛豫行为通常表现出与德拜弛豫的强烈偏差。从拉伸指数函数（KWW 函数）或幂律形式导出的弛豫时间分布可能是描述非德拜弛豫最常用的范例。它们本质上是以分析形式给出的连续光谱。然而，真正的无定形材料是否符合这种分布规律还有待讨论。在这里，我们测试典型金属玻璃 (MG) 作为一般非晶态固体的代表的假设。_{Cu 46}的力学光谱Zr ₄₇ Al ₇ MG 在宽频域中被动态力学分析技术探测。发现无论是KWW函数还是基于幂律的修正分数（MF）模型都能很好地描述实验数据。作为向前迈出的一步，我们将准点缺陷理论与 MF 模型相结合，从理论上揭示了 MG 中温度依赖性结构演化的特征。最后，将对应于实验数据的弛豫时间分布离散化，以论证理论上预测的 MG 微观结构异质性。