Anisotropic deformation behaviors of amorphous-crystalline nanolaminates investigated via molecular dynamics simulations

Amorphous-crystalline nanolaminates (ACNLs) composed of CuZr metallic glass layers and single crystal copper layers were constructed, and the anisotropy of the material deformation behaviors were investigated by conducting shear loadings on the ACNL sample in parallel deforming and serial deforming directions using molecular dynamics method. In parallel deforming mode, the yielding of the material was mainly triggered by generation of dislocations and slips in crystalline layer, and both crystalline and amorphous phases participated in the subsequent plastic deforming. In serial deforming mode, the results showed that the yielding and plastic deforming of the material was induced by shear localization of amorphous layers only. Amorphous-crystalline interfaces (ACIs) served as stress resistance weakness and dislocations breeding cradle in the former deforming mode while a strong connection of two phases in the later deforming mode. Furthermore, the increasing of crystalline layer thickness would promote the material shear modulus and shear strength in both deformation modes. The promotions and incentives varied and had dependence on the coupled deforming mechanisms. For the serial deforming mode, the shear moduli obtained from our simulations fitted the predicted ones from rule-of-mixture very well, while in the parallel deforming mode, the simulated shear moduli were much higher than predicted ones, which could be explained with the size effect induced by reduction of crystalline layer thickness surround with ACIs. (C) 2019 Elsevier B.V. All rights reserved.