Strain Rate Effects on the Mechanical Behavior of CoCrFeNiTi0.2 High-Entropy Alloy: A Molecular Dynamics Study
Saly Alammuri
Department of Materials Science & Engineering, University of Tennessee, Knoxville
This page shows a visualization of the final deformation state of a CoCrFeNiTix high-entropy alloy with a Ti composition of x = 0.2, obtained from molecular dynamics simulations. The snapshot corresponds to the final deformation state from the strain rate study at 0.002 1/ps seed three at twenty percent strain and displays the atomic positions within the simulation cell of 27,000 atoms.
Molecular dynamics simulations were performed to investigate the effect of strain rate on the mechanical behavior of the CoCrFeNiTi0.2 high-entropy alloy at 300 K. Building on the results of Project 1, which identified this composition as the strongest among the Ti series studied by Luo et al. [1], Project 2 extends the simulation study to examine how the deformation response changes across a range of strain rates. Four strain rates from 0.00025 to 0.002 1/ps were applied under uniaxial tensile loading. To quantify the effect of initial atomic configuration on the results, three independent thermal trajectories were generated using different velocity initialization seeds for each strain rate, resulting in twelve total simulations. Stress-strain curves were analyzed to extract elastic modulus, peak stress, and flow stress at each condition. Peak stress and flow stress showed no clear strain rate dependence within the observed scatter, with rate differences falling within run standard deviations of 0.77 to 1.10 GPa across all conditions. Run variability was the dominant source of scatter, with individual peak stress values ranging from 2.6 to 4.8 GPa within the same strain rate condition. Structural analysis confirmed Shockley partial dislocation activity and stacking fault formation consistent with FCC deformation mechanisms across all simulations.
References
1. Luo, Z., Wu, L., Ma, L., & Tang, Y. (2025). Molecular dynamics simulations of mechanical properties and phase structure for CoCrFeNiTix high-entropy alloys. Materials Today Communications, 43, 111789. https://doi.org/10.1016/j.mtcomm.2025.111789 posted: May 2026.Interactive Structures
Element Color Legend
2. Thompson, A. P., et al. (2022). LAMMPS - a flexible simulation tool for particle-based materials modeling at the atomic, meso, and continuum scales. Computer Physics Communications, 271, 108171. https://doi.org/10.1016/j.cpc.2021.108171
3. Liang, A., Goodelman, D. C., Hodge, A. M., Farkas, D., & Branicio, P. S. (2023). CoFeNiTix and CrFeNiTix high entropy alloy thin films microstructure formation. Acta Materialia, 257, 119163. https://doi.org/10.1016/j.actamat.2023.119163
updated: May 2026.