Notch sensitivity in nanoscale metallic glass specimens: Insights from continuum simulations |
| |
Institution: | 1. School of Civil Engineering & International Institute for Urban Systems Engineering, Southeast University, Nanjing 210096, China;2. System Consulting Dept. Aimnext Inc., Minato-Ku, Tokyo 105-0013, Japan |
| |
Abstract: | Recent experiments have shown that nano-sized metallic glass (MG) specimens subjected to tensile loading exhibit increased ductility and work hardening. Failure occurs by necking as opposed to shear banding which is seen in bulk samples. Also, the necking is generally observed at shallow notches present on the specimen surface. In this work, continuum finite element analysis of tensile loading of nano-sized notched MG specimens is conducted using a thermodynamically consistent non-local plasticity model to clearly understand the deformation behavior from a mechanics perspective. It is found that plastic zone size in front of the notch attains a saturation level at the stage when a dominant shear band forms extending across the specimen. This size scales with an intrinsic material length associated with the interaction stress between flow defects. A transition in deformation behavior from quasi-brittle to ductile becomes possible when this critical plastic zone size is larger than the uncracked ligament length. These observations corroborate with atomistic simulations and experimental results. |
| |
Keywords: | Metallic glass Notch sensitivity Shear band Brittle–ductile transition Non-local plasticity model |
本文献已被 ScienceDirect 等数据库收录! |
|