Molecular dynamics simulation for determining dislocation strengthening coefficient in BCC iron

Molecular dynamics simulation for determining dislocation strengthening coefficient in BCC iron

MIYAZAWA Naoki, HAMA Takayuki

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Abstract. Crystal plasticity models are promising numerical analysis methods for predicting and evaluating material forming processes. In crystal plasticity analyses, the dislocation density model, often based on the Bailey-Hirsch equation, is employed to represent the work hardening behavior of metallic materials. The dislocation strengthening coefficient is a proportional factor between the square root of dislocation density with the slip resistance. Therefore, the appropariate determination of the dislocation strengthening coefficient is crucial to perform reliable material forming analyses using crystal plasticity models. Previously, dislocation strengthening coefficients have been determined using dislocation dynamics simulations. However, dislocation dynamics simulations cannot accurately account for elastic anisotropy due to its computational cost. To address this limitation, we conducted molecular dynamics simulations to determine dislocation strengthening coefficient in bcc iron. Molecular dynamics simulations of dislocation-dislocation interaction analysis can be expected to determine the dislocation strengthening coefficient accurately, including the effects of elastic anisotropy of metallic materials.

Molecular Dynamics Simulation, Crystal-Plasticity Analysis, Dislocation Strengthening

Published online 4/24/2024, 6 pages
Copyright © 2024 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA

Citation: MIYAZAWA Naoki, HAMA Takayuki, Molecular dynamics simulation for determining dislocation strengthening coefficient in BCC iron, Materials Research Proceedings, Vol. 41, pp 983-988, 2024


The article was published as article 108 of the book Material Forming

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[1] R. Madec and L. P. Kubin, Dislocation strengthening in FCC metals and in BCC metals at high temperatures, Acta Mater. 126 (2017) 166-173.
[2] S. J. Zhou, D. L. Preston, P. S. Lomdahl and D. M. Beazley, Large-scale molecular dynamics simulations of dislocation interaction in copper, Science 279 (1998) 1525-1527.
[3] S. M. Hafez Haghighat, R. Scha¨ublin and D. Raabe, Atomistic simulation of the a0 <100> binary junction formation and its unzipping in body-centered cubic iron, Acta Mater. 64 (2014) 24-32.
[4] S. Plimpton, Fast parallel algorithms for short-range molecular dynamics, J. Compt. Phys. 117 (1995) 1-19.
[5] D. J. Bacon, D. M. Barrett and R. O. Scattergood, Anisotropic continuum theory of lattice defects, Prog. Mater. Sci. 23 (1979) 51-262.
[6] H. Chamati, N. I. Papanicolaou, Y. Mishin and D. A. Papaconstantopolous, Embedded-atom potential for Fe and its application to self-diffusion on Fe(100), Surf. Sci. 600 (2006) 1793-1803.
[7] G. de Wit and J.S. Koehler, Interactions of dislocations with an applied stress in anisotropic crystals, Phys. Rev. B, 116 (1959) 1113–1120.