Finite element analysis of tensile deformation of nanoglass-metallic glass laminate composites

Abstract

Nanolaminate composites consisting of alternate layers of Nanoglasses (NGs) and metallic glasses (MGs) have shown enhanced tensile ductility without great penalty on strength. Recent atomistic simulations on such NG-MG nanolaminate composites have revealed that peak stress attained in these materials do not follow rule of mixture. Also, a transition in deformation behaviour takes place when MG layer thickness is reduced below a threshold level which is correlated with average size of glassy grain in NG layer. However, the mechanistic reasons for this correlation is not well understood. Therefore, continuum simulations of tensile loading on NG-MG laminate composites are performed using thermodynamic consistent non-local plasticity model. Results show that interaction stress associated with flow defects such shear transformation zones (STZs) plays a pivotal role in the deformation response of laminate composites. Also, shear band width in these materials, scales with intrinsic material length associated with the interaction stress. Further, the material length with respect to MG layer thickness governs the transition in deformation behaviour. The present work may provide guidelines in developing highly ductile NG-MG laminate composites for practical engineering applications.