Li M, Xu C, Li Z, Li P, Tian X, Jiang W, Zaiser M, Fan H, Wang Q (2027)
Publication Type: Journal article
Publication year: 2027
Book Volume: 218
Article Number: 106851
DOI: 10.1016/j.jmps.2026.106851
Motion of pyramidal dislocations is a critical deformation mode for ensuring ductility of HCP (hexagonal close-packed) metals. However, the mechanical response mediated by pyramidal dislocations displays anomalous three-stage dependence on temperature. In this work, discrete dislocation dynamics (DDD) simulations are employed to study the effects of temperature on the mechanical response of Mg and Zn single-crystals under c-axis compression, by accounting for the temperature dependences of dislocation lattice friction stress, cross slip and basal transition. The three-stage temperature dependence of the yield stress is well predicted by the DDD simulations. In the first stage at low temperature, where the yield stress decreases with the increasing temperature, the plastic deformation in Mg is mostly mediated by first order pyramidal (Py-I) dislocations due to their low lattice friction stress. Few cross slip and basal transition events occur. In the second stage, where the yield stress increases at intermediate temperatures, screw Py-I dislocations cross slip onto second order pyramidal (Py-II) planes and near-edge Py-I dislocations transit onto basal planes. As a result, plastic deformation is mostly mediated by Py-II dislocations with a high lattice friction stress. In the third stage at elevated temperatures, screw Py-II dislocations cross slip onto Py-I planes. As a result, plastic deformation is again mediated by Py-I dislocations and thus the yield stress decreases.
APA:
Li, M., Xu, C., Li, Z., Li, P., Tian, X., Jiang, W.,... Wang, Q. (2027). Anomalous temperature dependence of mechanical response of HCP single-crystals. Journal of the Mechanics and Physics of Solids, 218. https://doi.org/10.1016/j.jmps.2026.106851
MLA:
Li, Mao, et al. "Anomalous temperature dependence of mechanical response of HCP single-crystals." Journal of the Mechanics and Physics of Solids 218 (2027).
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