Impact of a temperature‐dependent stretching exponent on glass relaxation
Impact of a temperature‐dependent stretching exponent on glass relaxation
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DOI：
10.1111/ijag.16548
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发表时间：
2022-01
影响因子：
2.1
通讯作者：
B. Hauke;M. Mancini;J. Mauro
中科院分区：
文献类型：
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作者：
B. Hauke;M. Mancini;J. Mauro
玻璃的非指数松弛行为由无量纲拉伸指数β决定，通常假设该指数为常数，但更准确地描述为温度的函数。在本文中，通过基于迭代微分方程的算法进行玻璃态材料的弛豫计算，以确定何时需要使用温度依赖性（或动态）拉伸指数来捕获假想温度分量的工业相关演变，这是工艺工程所必需的。结果揭示了液体脆性指数（m）的范围，其中静态β描述大致相当于动态β观察到的行为。然而，当考虑温度依赖性拉伸指数时，快速初级（α）弛豫模式在表现出过强或脆弱液体行为的系统中表现出独特的行为。在这期国际玻璃年特刊中，我们还就温度依赖β的重要性和影响提供了更广泛的视角。
The nonexponential relaxation behavior of glass is governed by the dimensionless stretching exponent,β, which is typically assumed to be a constant but is more accurately described as a function of temperature. Herein, relaxation calculations of glassy materials are undertaken via an iterative differential equation‐based algorithm to determine when the use of a temperature‐dependent (or dynamic) stretching exponent is required to capture the industrially relevant evolution of fictive temperature components, which is necessary for process engineering. Results reveal a range of liquid fragility index (m) in which a staticβdescription is roughly equivalent to the behavior observed with a dynamicβ. However, fast primary (α) relaxation modes demonstrate unique behavior in systems exhibiting excessively strong or fragile liquid behavior when a temperature‐dependent stretching exponent is considered. In this special issue dedicated to the International Year of Glass, we also provide broader perspectives regarding the importance and impact of a temperature‐dependentβ.