Effects of microscopic boundary conditions on the deformation behavior of small-volume metallic glasses

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:51

Article

Thamburaja, P.¹  Liu, J.² 

[1] Natl Univ Malaysia UKM, Dept Mech & Mat Engn, Bangi 43600, Malaysia

[2] Natl Univ Singapore, Dept Mech Engn, Singapore 117576, Singapore

关键词: Amorphous metals;    Constitutive model;    Strain gradient plasticity;    Finite-elements;    Microscopic boundary conditions;   

DOI  :  10.1016/j.ijsolstr.2014.09.011

来源: Elsevier

【 摘 要 】

Although large-volume metallic glasses (MGs) are susceptible to shear localization due to their intrinsically strain-softening response, recent experiments and molecular dynamics simulations have shown that small-volume MGs samples are able to exhibit work hardening response. Here, we seek to address two issues regarding the mechanical response of small-volume MGs at low homologous temperatures from a continuum-based modeling perspective: (1) are MGs capable of exhibiting a work hardening response, and (2) what is the physical mechanism which causes its work hardening response? Along with implementing a recently-developed finite-deformation, strain gradient plasticity-based constitutive model for MGs into a self-developed finite-element code, we study the tensile response of small-volume MG samples of various sizes through finite-element simulations. Our simulations show that small-volume MG samples are capable of exhibiting a work hardening response provided the following conditions are met: (a) the sample size is small enough, and (b) the appropriate microscopic boundary conditions for the free volume are imposed on the sample.

【 授权许可】

Free