|About this Abstract
|Materials Science & Technology 2020
|High Entropy Materials: Concentrated Solid Solution, Intermetallics, Ceramics, Functional Materials and Beyond
|Full “Ab-initio” Simulation of Field Evaporation of High Entropy Alloys
|Jiayuwen Qi, Christian Oberdorfer, Emmanuelle A. Marquis, Wolfgang Windl
|On-Site Speaker (Planned)
Atom probe tomography (APT) is frequently used to examine homogeneity vs. phase separation in concentrated solid solutions (CSS). Since phase separation is often slow because of the stifled dynamics in CSS, high resolution is needed to identify even small nuclei of second phases. In order to quantify reconstruction fidelity and the size and composition limits to reliably identify phase nucleation in APT, we perform forward-simulation of virtual samples with a fully physical approach and determine resolution limits and artifacts from a comparison with the reconstructed sample. For that, we apply the TAPSim-MD approach to high entropy alloy tips, which combines a finite-element based solution for the electric-field with molecular dynamics in LAMMPS. This approach allows determining evaporation sequence and local structural effects for CSS samples, effective evaporation field changes from alloying, and reconstruction fidelity and artifacts by comparing conventional reconstruction of the simulated evaporation sequence to the original virtual sample.