2018 年 59 巻 2 号 p. 230-236
Whereas adding a soft crystalline layer into metallic glasses can modify shear banding deformation and enhance plastic deformability, interface-related plastic behavior played a crucial role in the shear banding deformation of amorphous/crystalline nanolaminates (A/CNLs). In this work, the influence of amorphous/crystalline interface (ACI) and grain boundary (GB) on the shear banding deformation of amorphous Cu55(at%)Zr45(at%)/crystalline Cu nanolaminates were systemically studied using molecular dynamics (MD) simulations. On one hand, ACIs with both [110] and [111] interfacial crystal orientations were constructed. Results showed that localized interfacial sliding initiate at [111] interfacial orientation at an extremely low stress, due mainly to abrupt compositional mixing at the ACI. On the other hand, GB either vertical or parallel to ACI were specially designed. Large numbers of pre-existing boundary dislocation activations along the vertical GB were shown to facilitate the shear banding formation of A/CNLs. In contrast, interfacial dislocation emission and dislocation slip transmission across the parallel GB postponed the shear banding formation. These results enable controlling shear banding deformation of A/CNLs and ensure their reliable application via nanoscale interfacial design.
