J. Mater. Sci. Technol. ›› 2025, Vol. 213: 98-108.DOI: 10.1016/j.jmst.2024.06.030

• Research Article • Previous Articles     Next Articles

Modeling segregated solutes in plastically deformed alloys using coupled molecular dynamics-Monte Carlo simulations

Hariprasath Ganesana,c,1,*, Godehard Sutmannb,c   

  1. aInstitute for Advanced Simulation - Materials Data Science and Informatics (IAS-9), Forschungszentrum Jülich, Jülich, Germany;
    bJülich Supercomputing Centre (JSC), Institute for Advanced Simulation (IAS), Forschungszentrum Jülich, Jülich, Germany;
    cInterdisciplinary Centre for Advanced Materials Simulation (ICAMS), Ruhr-University Bochum, Bochum, Germany
  • Received:2024-04-30 Revised:2024-06-18 Accepted:2024-06-18 Published:2025-04-01 Online:2025-04-01
  • Contact: *E-mail address: h.ganesan@fz-juelich.de (H. Ganesan) URL: https://www.fzj.de (H. Ganesan)
  • About author:1Currently at Forschungszentrum Jülich

Abstract: A microscopic understanding of the complex solute-defect interaction is pivotal for optimizing the alloy's macroscopic mechanical properties. Simulating solute segregation in a plastically deformed crystalline system at atomic resolution remains challenging. The objective is to efficiently model and predict a physically informed segregated solute distribution rather than simulating a series of diffusion kinetics. To address this objective, we coupled molecular dynamics (MD) and Monte Carlo (MC) methods using a novel method based on virtual atoms technique. We applied our MD-MC coupling approach to model off-lattice carbon (C) solute segregation in nanoindented Fe-C samples containing complex dislocation networks. Our coupling framework yielded the final configuration through efficient parallelization and localized energy computations, showing C Cottrell atmospheres near dislocations. Different initial C concentrations resulted in a consistent trend of C atoms migrating from less crystalline distortion to high crystalline distortion regions. Besides unraveling the strong spatial correlation between local C concentration and defect regions, our results revealed two crucial aspects of solute segregation preferences: (1) defect energetics hierarchy and (2) tensile strain fields near dislocations. The proposed approach is generic and can be applied to other material systems as well.

Key words: Molecular dynamics, Monte Carlo, Virtual atoms, Solute segregation, Cottrell atmosphere, Off-lattice