From generalized stacking fault energies to dislocation properties: Five-energy-point approach and solid solution effects in magnesium

0450468 - ÚFM 2016 RIV US eng J - Článek v odborném periodiku
Pei, Z. - Ma, D. - Friák, Martin - Svendsen, B. - Raabe, D. - Neugebauer, J.
From generalized stacking fault energies to dislocation properties: Five-energy-point approach and solid solution effects in magnesium.
Physical Review. B. Roč. 92, č. 6 (2015), 064107-1-064107-11. ISSN 1098-0121
Institucionální podpora: RVO:68081723
Klíčová slova: metals * ab initio * Peierls–Nabarro model
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
Impakt faktor: 3.736, rok: 2014

Using ab initio calculations and symmetrized plane waves, we analyze the basal-plane generalized stacking fault energies in pure Mg and Mg-Y alloys and show that the knowledge of energies of only five specific points is sufficient to accurately predict the core structures and Peierls stresses of a-type edge dislocations. Our five-point approach substantially reduces the computational cost related to the Peierls-Nabarro (PN) model and allows for a high-throughput application of the PN model to study Peierls stress changes in Mg upon alloying.We employ our approach to study Mg binary alloys containing nine rare-earth (RE) and 11 other solutes. Based on the Peierls stresses of these 20 Mg alloys calculated from the Peierls-Nabarro model, the solutes are divided into three groups: (i) the first group lead to more compact dislocation core structures and larger Peierls stresses than in pure Mg. (ii) Elements in the second group, change the core widths and Peierls stresses moderately. (iii) The solutes in the third group extend the stacking fault width, and the Peierls stresses are low.
Trvalý link: http://hdl.handle.net/11104/0251852