Simulation and Modeling to Reveal the Mechanisms of Microstructure Change and Phase Transformation

Simulation and Modeling to Reveal the Mechanisms of Microstructure Change and Phase Transformation

The overall objectives of the modeling efforts are to: (a) obtain a fundamental understanding of the mechanisms from atomistic to microscopic length scales underlying microstructure evolution and phase transformations (fcc to hcp, bcc to fcc) in AM CCSs subjected to high strain rate and high pressure, and (b) interpret and correlate with the ultrafast X-ray dynamic compression experiments. To this end, we will integrate atomistic simulation, neural network-informed kinetic Monte Carlo (kMC), and potential energy landscape (PEL) sampling to obtain the research goal. We hypothesize that the chemical and structural heterogeneity inherent in multi-component CCSs can largely tune the degree of stacking fault energy and dislocation slip resistance, and hence the microstructure evolution and phase transformation that are distinct from the traditional dilute alloys. To test the hypothesis and obtain the deformation physics.

Deformation microstructure of grains after dynamic loading. Grains have one (a), two (b) and three (c) activated slip planes. Phase transformation (fcc to hcp), twining, and stacking fault (SF) are labeled.