Rheology and Ultrasonic Properties of Metallic Glass-Forming Liquids: A Potential Energy Landscape Perspective
Rheology and Ultrasonic Properties of Metallic Glass-Forming Liquids: A Potential Energy Landscape Perspective
复制标题
DOI：
10.1016/j.jallcom.2007.11.151
复制
发表时间：
2007-08
期刊：
影响因子：
5
通讯作者：
W. Johnson;M. Demetriou;John S. Harmon;M. Lind;K. Samwer
中科院分区：
文献类型：
--
作者：
W. Johnson;M. Demetriou;John S. Harmon;M. Lind;K. Samwer
金属玻璃形成液体的流动可以被建模为跨越能量势垒的固有状态之间的构型跳跃，所述能量势垒被假设为平均正弦曲线。这样的处理引起的粘度和isoconstructional剪切模量之间的函数关系，这导致了一个流变学定律，能够有效地模拟牛顿和非牛顿粘度的金属玻璃形成液体在很宽的范围内的脆性。在过冷液体区域内收集的高频超声波数据与流变数据相关，从而证实了所提出的处理方法的有效性。热激发或机械变形引起的剪切模量的变化与所测得的储存焓的变化相关，这表明这些材料的弹性软化由剪切模量和构型势能之间的独特的函数关系来控制。
The flow of metallic glass-forming liquids can be modeled as configurational hopping between inherent states across energy barriers that are assumed to be on average sinusoidal. Such treatment gives rise to a functional relation between viscosity and isoconfigurational shear modulus, which leads to a rheological law capable of effectively simulating the Newtonian and non-Newtonian viscosity of metallic glass-forming liquids over a broad range of fragility. High-frequency ultrasonic data gathered within the supercooled liquid region are shown to correlate well with rheological data, thus confirming the validity of the proposed treatment. Variations in shear modulus induced either by thermal excitation or mechanical deformation are correlated to variations in the measured stored enthalpy, suggesting that the elastic softening of these materials is govern by a unique functional relation between shear modulus and configurational potential energy.