Multiscale Simulation of Defects and Shear Localization in Metallic Glasses

Johns Hopkins University, Baltimore MD

Investigators

Abstract

0084886 This research addresses one of the long outstanding fundamental problems in metallic glasses: microscopic mechanisms of deformation. Metallic glass deforms in highly localized zones called shear bands. The inability to spread the local deformation is the dominant factor affecting the fracture strength, toughness, and widespread applications of amorphous metals. The aim of this work is to search and identify defects that promote deformation in amorphous metals. To answer the challenges posed 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 model shear band propagation on mesoscopic scale. We expect the knowledge generated from the multiscale simulations to lay a foundation for the future development of theoretical models, and provide guidance to experiments in synthesis, testing and application of metallic glasses and their composites