|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Bulk Metallic Glasses XV
||Density Evolution, Strain Hardening, and Plastic Flow of a Metallic Glass in a Notched Tensile Test
||Yonghao Sun, Mantong Zhao, Peter Kenesei, Jun-Sang Park, Todd Hufnagel
|On-Site Speaker (Planned)
It has recently been reported that metallic glasses can show significant plastic deformation and strain hardening in tensile tests of deeply-notched specimens, and it has further been proposed that this unusual behavior results from diffusive annihilation of free volume driven by the hydrostatic component of stress in the notched region. To examine this hypothesis, we have performed in situ evaluations of the density of notched tensile specimens under load using high-energy x-ray absorption. We see only limited evidence for densification (free volume annihilation). Instead, we show that extensive delocalized ("homogeneous") plastic flow is made possible by the suppression of shear band activity due to the non-uniform, multiaxial stress state around the notch. We further show that prior observations of hardening in the notched region (previously presented as evidence of free volume annihilation there) can be explained on the basis of tensile residual stresses that develop upon unloading.
||Planned: Supplemental Proceedings volume