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Twinning pathways in Fe and Fe–Cr alloys from first-principles theory
- Source :
- Acta Materialia. 215:117094
- Publication Year :
- 2021
- Publisher :
- Elsevier BV, 2021.
-
Abstract
- Using density-functional theory, we determine the generalized stacking fault energy (GSFE) for the { 1 1 ¯ 2 } 〈 1 ¯ 11 〉 twinning system in ferromagnetic (FM) body-centered cubic Fe and Fe-Cr alloys with molar fraction of Cr ≤ 0.5 . We adopt both reflection and isosceles twinning pathways and reveal the magnetic ordering effects on the GSFE by contrasting the FM results to those obtained for the magnetically disordered paramagnetic (PM) state. The results show that the isosceles twin boundary configuration is energetically preferred in this binary. The loss of long-range magnetic order lowers the GSFE amplitude but increases the twin boundary migration (TBM) energy regardless of the Cr content. The twin boundary formation (TBF) energy and the TBM energy show non-linear dependences on Cr content in the FM and PM states, and the effect of Cr on these properties critically depends on the magnetic state. We discuss our results in regard to the stable twin boundary structure and deformation twinning experimentally observed in homogeneous Fe-50 wt.% Cr alloy up to temperatures slightly above the magnetic ordering temperature.
- Subjects :
- 010302 applied physics
Materials science
Polymers and Plastics
Condensed matter physics
Alloy
Metals and Alloys
02 engineering and technology
engineering.material
021001 nanoscience & nanotechnology
Mole fraction
01 natural sciences
Electronic, Optical and Magnetic Materials
Paramagnetism
Ferromagnetism
Stacking-fault energy
Ferrite (iron)
0103 physical sciences
Ceramics and Composites
engineering
0210 nano-technology
Crystal twinning
Néel temperature
Subjects
Details
- ISSN :
- 13596454
- Volume :
- 215
- Database :
- OpenAIRE
- Journal :
- Acta Materialia
- Accession number :
- edsair.doi...........764884d50b0d385fedd2138cf50d22d8