A02 – Atomistic Simulation of Dislocation Processes

PI(s): Erik Bitzek (MPIE)

SFB researchers: Zhuocheng Xie (IMM)

The aim of project A02 is to investigate the fundamental mechanisms of dislocation-mediated plasticity in the dominant precipitate phases of the Mg-Al-Ca alloy system. Large-scale molecular dynamics (MD) simulations of compression and nanoindentation of Laves phases (left figure) revealed the importance of synchro-Shockley dislocations. These were shown by nudged elastic band (NEB) calculations to glide by kink pair nucleation and propagation. This process can be influenced by the local chemical composition at the partial dislocation cores. Hybrid Monte Carlo (MC)/MD furthermore showed that the partial dislocation core structure of dislocations in Laves phases can change with composition and temperature (right figure). Similar defect phase diagrams were identified for stacking faults in Laves phases. Additional areas of studies include the interphase boundaries between Laves phases and the Mg matrix phase, dislocations and grain boundaries in the Mg solid solution and fracture of Laves phases. The project collaborates closely with the experimental projects (A03-05, B01 and C02) and with A06 regarding the development and use of Machine Learning potentials.




  • [1] J. Guénolé, M. Zubair, S. Roy, Z. Xie, M. Lipińska-Chwałek, S. Sandlöbes-Haut and S. Korte-Kerzel, (2021) Exploring the transfer of plasticity across Laves phase interfaces in a dual phase magnesium alloy. Materials & Design, 202, p.109572. https://doi.org/10.1016/j.matdes.2021.109572
  • [2] Z. Xie, D. Chauraud, E. Bitzek, S. Korte-Kerzel and J. Guénolé, (2021) Laves phase crystal analysis (LaCA): Atomistic identification of lattice defects in C14 and C15 topologically close-packed phases. Journal of Materials Research, 36(10), pp.2010-2024. doi.org/10.1557/s43578-021-00237-y
  • [3] Z. Xie, D. Chauraud, A. Atila, E. Bitzek, S. Korte-Kerzel and J. Guénolé, (2022) Unveiling the mechanisms of motion of synchro-Shockley dislocations in Laves phases. arXiv preprint arXiv:2205.02669.  https://doi.org/10.48550/arXiv.2205.02669
  • [4] R. Pei, Z. Xie, S. Korte-Kerzel, J. Guénolé and T. Al-Samman, (2022) Atomistic origin of the anisotropic grain boundary segregation in a Mg-Mn-Nd alloy. arXiv preprint arXiv:2201.02884. doi.org/10.48550/arXiv.2201.02884