Zr60Al10Co20Ag10非晶合金动态力学弛豫和晶化动力学研究

Dynamic Mechanical Relaxation and Crystallization Kinetics of Zr60Al10Co20Ag10 Metallic Glass

摘要:

通过动态力学分析研究了Zr₆₀Al₁₀Co₂₀Ag₁₀非晶合金的弛豫行为，并结合示差扫描量热法探讨了其热稳定性和晶化动力学。研究表明，该合金的损耗模量表现出显著的α弛豫峰宽化特征；且其α弛豫激活能较低（3.78±0.21 eV），这与晶化行为的提前进行密切相关。基于Kohlrausch-Williams-Watts（KWW）模型，分析了其动态力学性能的温度与频率依赖性。结果显示，该合金具有较小的Kohlrausch指数 β_KWW，反映出其具有较宽的弛豫时间分布以及显著的动力学非均匀性。利用Kissinger方程计算得出，该非晶合金的晶化开始激活能E_x、第一晶化峰激活能E_p1和第二晶化峰激活能E_p2分别为424、420和271 kJ/mol，显示出良好的热稳定性。晶化动力学分析表明，其第一晶化峰对应于扩散受控型结晶过程，其Avrami指数=1.97±0.33，符合扩散主导的生长理论。

Abstract:

The dynamic mechanical relaxation behavior of a Zr₆₀Al₁₀Co₂₀Ag₁₀ metallic glass was investigated by dynamic mechanical analysis, and its thermal stability and crystallization kinetics were further examined by thermal analysis. The results show that the loss modulus of this alloy exhibits a significant broadening α-relaxation peak, and the relatively low activation energy of α-relaxation (3.78±0.21 eV) is associated with the early onset of crystallization. The temperature and frequency dependence of the dynamic mechanical relaxation behavior were analyzed using the Kohlrausch-Williams-Watts (KWW) model, yielding a low Kohlrausch exponent (β_KWW) value that indicates a wide distribution of relaxation time and pronounced dynamic heterogeneity. Using Kissinger equation, the activation energy for the onset of crystallization E_x, the first crystallization peak activation energy E_p1, and the second crystallization peak activation energy E_p2 of this metallic glass are calculated to be 424, 420, and 271 kJ/mol, respectively, suggesting good thermal stability. Crystallization kinetics results show that the first crystallization peak corresponds to a diffusion-controlled process, with an Avrami index =1.97±0.33, which is consistent with the diffusion-dominated growth theory.