Multiscale Simulation of Defects and Shear Localization in Metallic Glasses

[00:84886]本研究解决了金属玻璃长期以来突出的基本问题之一：微观变形机制。金属玻璃在称为剪切带的高度局部区域变形。局部变形不能扩散是影响非晶态金属断裂强度、韧性和广泛应用的主要因素。这项工作的目的是寻找和识别促进非晶金属变形的缺陷。为了应对非晶材料缺乏长程有序所带来的挑战，我们计划使用广泛的多尺度计算机模拟。我们将开发表征自由体积的算法，非平衡模拟方法来模拟局部散热，识别扩展缺陷（如位错）的技术，最后，开发随机动态方法来模拟中观尺度上的剪切带传播。我们期望从多尺度模拟中获得的知识为理论模型的未来发展奠定基础，并为金属玻璃及其复合材料的合成、测试和应用实验提供指导

0084886This research addresses one of the long outstandingfundamental problems in metallic glasses: microscopic mechanisms ofdeformation. Metallic glass deforms in highly localized zones calledshear bands. The inability to spread the local deformationis the dominant factor affecting the fracture strength, toughness,and widespread applications of amorphous metals. The aim of thiswork is to search and identify defects that promotedeformation in amorphous metals. To answer the challengesposed by the lack of long-range order in amorphous materials, we plan to use extensive, multiscale computer simulations.We will develop algorithms to characterize free volumes,non-equilibrium simulation methods to model local heat dissipation,techniques to identify extended defects such as dislocations,and finally, development of stochastic dynamic method to modelshear band propagation on mesoscopic scale. We expect theknowledge generated from the multiscale simulations to lay afoundation for the future development of theoretical models,and provide guidance to experiments in synthesis, testingand application of metallic glasses and their composites