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: V.V. Borovikov, M.I. Mendelev, N.A. Zarkevich, T.M. Smith, and J.W. Lawson (2024), "Effect of Nb solutes on the Kolbe mechanism for microtwinning in Ni-based superalloys", International Journal of Plasticity178, 104004. DOI: 10.1016/j.ijplas.2024.104004.
Abstract: As the operating temperature of jet turbine engines increase, creep becomes the life-limiting property for turbine disks and blades. At intermediate temperatures, around 600-800 °C, microtwinning contributes significantly to creep strain in these alloys. Therefore, understanding how microtwins form and grow is critical to improving the creep life of future Ni-base superalloy components. In addition, exploring the effect of different alloying elements, such as Nb and Ta, on the formation of microtwins is critical for future alloy development. Several mechanisms of microtwinning have been proposed among which the Kolbe mechanism, based on thermally activated reordering, is believed to be dominant. In this work we employ atomistic simulation to investigate the effects of Nb solutes on the Kolbe mechanism. The simulation demonstrates that Nb atoms significantly slow down the reordering processes, explaining the experimentally observed improvement in the creep resistance.
Notes: As noted by Mikhail Mendelev, "This potential was specially developed to simulate the dislocation migration in γ (Al solution in Ni) and γ' (Ni3Al L12) phases. The potential provides the correct description of the thermodynamics of these phases including melting temperatures and solubility regions. The potential also correctly reproduces the elastic properties and stacking fault energies of the γ' phase." Update Sept 16, 2025: Citation information has been added and the potential's ID has been updated (used to be 2022--Mendelev-M-I--Ni-Al).