Scudino S, Bian J J, Shakur Shahabi H, Şopu D, Sort J, Eckert J, Liu G
IFW Dresden, Institute for Complex Materials, Helmholtzstraße 20, D-01069, Dresden, Germany.
State Key Laboratory for Mechanical Behaviors of Materials, School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
Sci Rep. 2018 Jun 15;8(1):9174. doi: 10.1038/s41598-018-27285-5.
A prerequisite to utilize the full potential of structural heterogeneities for improving the room-temperature plastic deformation of bulk metallic glasses (BMGs) is to understand their interaction with the mechanism of shear band formation and propagation. This task requires the ability to artificially create heterogeneous microstructures with controlled morphology and orientation. Here, we analyze the effect of the designed heterogeneities generated by imprinting on the tensile mechanical behavior of the ZrTiCuNiAl BMG by using experimental and computational methods. The imprinted material is elastically heterogeneous and displays anisotropic mechanical properties: strength and ductility increase with increasing the loading angle between imprints and tensile direction. This behavior occurs through shear band branching and their progressive rotation. Molecular dynamics and finite element simulations indicate that shear band branching and rotation originates at the interface between the heterogeneities, where the characteristic atomistic mechanism responsible for shear banding in a homogeneous glass is perturbed.
充分利用结构不均匀性来改善大块金属玻璃（BMG）的室温塑性变形的一个先决条件是了解它们与剪切带形成和扩展机制的相互作用。这项任务需要具备人工创建具有可控形态和取向的异质微观结构的能力。在此，我们通过实验和计算方法分析了通过压印产生的设计不均匀性对ZrTiCuNiAl BMG拉伸力学行为的影响。压印材料具有弹性不均匀性，并表现出各向异性的力学性能：强度和延展性随着压印与拉伸方向之间加载角度的增加而增加。这种行为是通过剪切带分支及其逐渐旋转发生的。分子动力学和有限元模拟表明，剪切带分支和旋转起源于不均匀性之间的界面，在均匀玻璃中负责剪切带形成的特征原子机制在该界面处受到干扰。
