|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Hume-Rothery Symposium on Connecting Macroscopic Materials Properties to Their Underlying Electronic Structure: The Role of Theory, Computation, and Experiment
||Integrated Computational Modeling of Solute Segregation to Defect, Segregation Transition, Localized Phase Transformation and Dislocation Transformation, All Starting from Ab Initio Calculations
||Longsheng Feng, You Rao, Ashton Egan, Maryam Ghazisaeidi, Michael Mills, Yunzhi Wang
|On-Site Speaker (Planned)
Extended defects in crystalline solids such as dislocations, grain boundaries, stacking faults, and deformation twins may cause solute re-distribution, alter phase equilibria and change phase transformation behavior. If the extended defects are generated during deformation, dynamic phase transformations may occur at these defects, which will alter the deformation pathway and hence impact significantly the mechanical properties. In this presentation, we show that starting from ab initio calculations of generalized stacking fault (GSF) energy and interaction energy between solute and the extended defects, one can predict (a) the structures of these extended defects and novel deformation mechanisms such as dislocation transformation by using the microscopic phase field method; (b) Solute segregation at the defects by using segregation isotherm through coupling with thermodynamic databases; (c) localized phase transformation (LPT) at stacking faults, offering either LPT-strengthening or LPT-softening during deformation. The work is supported by NSF under DMREF programs.