|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Bulk Metallic Glasses XIX
||Anelastic spectra and plasticity -- effects of relaxation and rejuvenation
||Michael Atzmon, Tianjiao Lei, JongDoo Ju
|On-Site Speaker (Planned)
Thermally activated, localized shear transformations were proposed by Orowan decades ago as the mechanism of both permanent and reversible deformation, i.e., plasticity and anelasticity, of disordered solids. Significant progress has been made since, involving experiment, theory and atomistic simulations. Major challenges have included the lack of a known imaging mechanism, and computationally inaccessible length and time scales required to simulate thermally activated events. We have performed quasi-static measurements of anelastic recovery of metallic glasses, spanning ten orders of magnitude in time. Time-constant spectra computed from the data revealed an atomically-quantized hierarchy of shear transformation zones (STZs). The methodology has allowed for detailed characterization of the effects of structural relaxation and cryogenic rejuvenation, and detailed analysis of literature data. Spectra of similar alloys that differ in their plasticity indicate a correlation between the latter and a high concentration of large/slow potential STZs. The results will be reviewed, and alternative approaches critiqued.
||Mechanical Properties, Modeling and Simulation,