Atomistic Study of the Role of Defects on α → ϵ Phase Transformations in Iron under Hydrostatic Compression
1
Institute of Applied Mechanics, Clausthal University of Technology, Arnold-Sommerfeld-Straße, D-38678 Clausthal-Zellerfeld, Germany
2
Center of Engineering, Modeling and Applied Social Sciences, Federal University of ABC, 09210-580 Santo André, Brazil
*
Author to whom correspondence should be addressed.
Metals 2019, 9(10), 1040; https://doi.org/10.3390/met9101040
Received: 12 August 2019
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Revised: 16 September 2019
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Accepted: 17 September 2019
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Published: 24 September 2019
(This article belongs to the Special Issue Multiscale Modeling of Materials and Processes)
It has long been known that iron undergoes a phase transformation from body-centered cubic/ structure to the metastable hexagonal close-packed/ phase under high pressure. However, the interplay of line and planar defects in the parent material with the transformation process is still not fully understood. We investigated the role of twins, dislocations, and Cottrell atmospheres in changing the crystalline iron structure during this phase transformation by using Monte Carlo methods and classical molecular dynamics simulations. Our results confirm that embryos of -Fe nucleate at twins under hydrostatic compression. The nucleation of the hcp phase is observed for single crystals containing an edge dislocation. We observe that the buckling of the dislocation can help to nucleate the dense phase. The crystal orientations between the initial structure -Fe and -Fe in these simulations are . The presence of Cottrell atmospheres surrounding an edge dislocation in bcc iron retards the development of the hcp phase.
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Keywords:
solid–solid transitions; iron; carbon; molecular dynamics; cottrell atmosphere
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MDPI and ACS Style
Luu, H.-T.; Veiga, R.G.A.; Gunkelmann, N. Atomistic Study of the Role of Defects on α → ϵ Phase Transformations in Iron under Hydrostatic Compression. Metals 2019, 9, 1040. https://doi.org/10.3390/met9101040
AMA Style
Luu H-T, Veiga RGA, Gunkelmann N. Atomistic Study of the Role of Defects on α → ϵ Phase Transformations in Iron under Hydrostatic Compression. Metals. 2019; 9(10):1040. https://doi.org/10.3390/met9101040
Chicago/Turabian StyleLuu, Hoang-Thien, Roberto G. A. Veiga, and Nina Gunkelmann. 2019. "Atomistic Study of the Role of Defects on α → ϵ Phase Transformations in Iron under Hydrostatic Compression" Metals 9, no. 10: 1040. https://doi.org/10.3390/met9101040
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