|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Fracture Properties and Residual Stresses in Small Dimensions
||Tensile Deformation Behaviour of Notched Nano-scale Metallic Glass Specimens
||Narasimhan Ramarathinam, Indrasen Singh
|On-Site Speaker (Planned)
Nano-scale metallic glass (MG) specimens exhibit homogeneous plastic deformation and necking under tensile loading in contrast to bulk specimens which fail by unstable shear band (SB) propagation. Necking is found to be initiated by shallow notches on the specimen surface. Although molecular dynamics simulations indicate similar response, the mechanistic origin of the above quasi-brittle to ductile transition is not well understood. The aim of the present work is to gain insights on the above phenomenon from continuum finite element simulations using a non-local plasticity model. The results show that the plastic zone in front of the notch attains a saturation size rps when a dominant SB spreads across the specimen. The SB width as well as rps scale with an intrinsic material length that characterizes the interaction stress between flow defects. Failure mode transition from unstable SB propagation to necking is governed by ratio of rps to uncracked ligament length.