Strain Localization during Tension and Compression Test and the Plasticity of Cu-Zr Model Amorphous Alloy

Abstract

Elastostatic and quasistatic compression tests performed in a widecompositional range of the binary Cu-Zr amorphous alloys have demonstratedthat the difference in the structural disordering (or softening, shear localizationand energy absorption) during deformation control the plasticity of amorphousalloys. If the binary Cu-Zr amorphous alloys can be deformed plastically with afew percent under compression mode, these alloys break without any plasticitywhen deformed under uniaxial tensile mode. To investigate these phenomena,we explore the deformation behavior of Cu65Zr35 during tension and compressiontests using molecular dynamics simulations. The results demonstrated that whentensile stress is applied to the alloy, the degree of structural softening (strainlocalization) is high and the yield strength decreased when comparing to thecompressive stress. We clarify this different deformation behavior during tensionand compression tests, by exploring the relationship between the stress stateduring tension and compression modes and its effect on the strain localization.