Correlation between plasticity and other materials properties of Cu-Zr bulk metallic glasses: An atomistic simulation study

Abstract

The correlation between experimentally observed plasticity and various materials properties that have been mentioned as being related to the mechanical properties of bulk metallic glasses (BMGs) has been investigated for Cu-Zr binary BMG alloys using a molecular dynamics simulation. Most of the properties examined show a roughly comparable correlation with plasticity, but the accuracy is not sufficient to be used for alloy design. The pentagon fraction obtained from a Voronoi polygon analysis and atomic displacement during plastic deformation directly computed using the atomistic approach can be selected as quantities that have an acceptable correlation with plasticity, even though the clearness and the statistical stability are unsatisfactory. The fractional volume change of mixing is proposed as a new materials property that shows a clear and statistically stable correlation with plasticity, and its physical origin as a tool to estimate the plasticity of and to design BMG alloys with improved plasticity is discussed. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.