Calculation update! New properties have been added to the website for dislocation monopole core structures, dynamic relaxes of both crystal and liquid phases, and melting temperatures! Currently, the results for these properties predominately focus on EAM-style potentials, but the results will be updated for other potentials as the associated calculations finish. Feel free to give us feedback on the new properties so we can improve their representations as needed.
Warning! Note that elemental potentials taken from alloy descriptions may not work well for the pure species. This is particularly true if the elements were fit for compounds instead of being optimized separately. As with all interatomic potentials, please check to make sure that the performance is adequate for your problem.
Citation: J.S. Lee, G. Xu, J.S. Suh, J.H. Bae, B.-C. Suh, Y.M. Kim, W.-S. Ko, and B.-J. Lee (2024), "Atomistic investigation into the formation of axial weak twins during the compression of single-crystal Mg nanopillars", Acta Materialia263, 119512. DOI: 10.1016/j.actamat.2023.119512.
Abstract: Molecular dynamics simulations are performed to provide a detailed atomic-level understanding of the deformation and twinning behavior of single-crystal Mg nanopillars under [0001] and [0110] compressions. To that end, a new interatomic potential based on the second nearest-neighbor modified embedded-atom method is developed to improve the reproducibility of overall physical properties, particularly in relation to plastic deformation. Further nanopillar compression analysis reveals that the simulation based on the developed potential satisfactorily reproduces the experimentally observed slip and twinning phenomena, consistent with theoretical interpretations. The present simulation results provide visual evidence for differentiated deformation characteristics of single-crystal Mg in different loading orientations and for the detailed nucleation and growth mechanisms of the recently discovered unconventional twins known as "axial weak twins" that exhibit 90° and 62° orientation relationships with the parent matrix. Our investigation reveals that the formation of both weak twins is commonly associated with atomic shuffling in the high-stress state, and the nucleation of the 62° weak twin is facilitated by pyramidal I dislocations.
See Computed Properties Notes: These files were created by extracting the Mg element parameters from the 2026--Ahn-H-H--Mg-Sc--LAMMPS--ipr1 listing. The cutoff distance was set to 4.5 Angstrom and the cutoff truncation set to 1.0 Angstrom to match what was used in the above reference. The files are posted with approval from Won-Seok Ko. File(s):