|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||Deformation Induced Microstructural Modification
||A First Principles Criterion for Microstructure Evolution in Deformation Twinned FCC Materials
||Matthew Daly, Ritesh Jagatramka, Junaid Ahmed
|On-Site Speaker (Planned)
The process of deformation twinning influences the flow behavior of FCC metals through two signature features – plasticity accommodation and dynamic crystal refinement. These dual features raise an interesting question: under which conditions do FCC materials nucleate or thicken deformation twins in response to plastic deformation? Nucleation-favored twinning causes a rapid segmentation of a microstructure, whereas thickening-favored twinning leads to a unit-step decrease in crystal size. Here, a first-principles criterion to evaluate the competition between nucleation and thickening of deformation twins in FCC materials is presented. This criterion is based on activation barriers retrieved from the generalized stacking fault energy landscapes of common FCC materials and is therefore free from phenomenological fitting. Microstructure parameters such as the twin density and dislocation mean free path can be readily accessed through this approach. Ongoing efforts to expand this criterion to predict microstructure evolution in concentrated FCC solid solutions are also overviewed.