Lenchuk, Olena ; Rohrer, Jochen ; Albe, Karsten (2015)
Atomistic modelling of zirconium and silicon segregation at twist and tilt grain boundaries in molybdenum.
In: Journal of Materials Science, 51
doi: 10.1007/s10853-015-9494-y
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
We investigate the influence of Zr and Si seg- regation on the cohesive strength of grain boundaries (GBs) in molybdenum using density functional theory calcula- tions. A tilt Sigma 5(310)[001] and twist Sigma 5[001] GB in bicrystal geometry are chosen as structural models. We determine the site preference of Zr and Si for segregation in these GBs and define the segregation energy. We quantify the effect of solutes on the stability of the GBs against brittle fracture by means of the Griffith criterion (work of separation). Additionally, the intrinsic bond strength of the GB containing a solute is quantified by means of the the- oretical strength. The results show that Zr and Si tend to segregate at the GBs if the low-energy insertion sites are available. However, the work of separation is decreased by the presence of Zr and Si and even in the presence of oxygen, there is no increase of the Griffith energy. Con- tributions of strain and chemical energy are analysed in order to explain our findings
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2015 |
| Autor(en): | Lenchuk, Olena ; Rohrer, Jochen ; Albe, Karsten |
| Art des Eintrags: | Bibliographie |
| Titel: | Atomistic modelling of zirconium and silicon segregation at twist and tilt grain boundaries in molybdenum |
| Sprache: | Englisch |
| Publikationsjahr: | 19 Oktober 2015 |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Journal of Materials Science |
| Jahrgang/Volume einer Zeitschrift: | 51 |
| DOI: | 10.1007/s10853-015-9494-y |
| Kurzbeschreibung (Abstract): | We investigate the influence of Zr and Si seg- regation on the cohesive strength of grain boundaries (GBs) in molybdenum using density functional theory calcula- tions. A tilt Sigma 5(310)[001] and twist Sigma 5[001] GB in bicrystal geometry are chosen as structural models. We determine the site preference of Zr and Si for segregation in these GBs and define the segregation energy. We quantify the effect of solutes on the stability of the GBs against brittle fracture by means of the Griffith criterion (work of separation). Additionally, the intrinsic bond strength of the GB containing a solute is quantified by means of the the- oretical strength. The results show that Zr and Si tend to segregate at the GBs if the low-energy insertion sites are available. However, the work of separation is decreased by the presence of Zr and Si and even in the presence of oxygen, there is no increase of the Griffith energy. Con- tributions of strain and chemical energy are analysed in order to explain our findings |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Materialmodellierung Zentrale Einrichtungen > Hochschulrechenzentrum (HRZ) > Hochleistungsrechner Zentrale Einrichtungen > Hochschulrechenzentrum (HRZ) Zentrale Einrichtungen |
| Hinterlegungsdatum: | 23 Okt 2015 11:35 |
| Letzte Änderung: | 16 Sep 2016 05:35 |
| PPN: | |
| Sponsoren: | The research was supported by the German Research Foundation (DFG) through Project AL 578/9-1 within the Research Unit FOR 727 ‘‘Beyond Nickel-Base Superalloys’’. The authors gratefully acknowledge the computing time granted by, the John von Neumann Institute for Computing (NIC) and provided on the supercomputer JUROPA at Jülich Supercomputing Center (JSC). Computational time was also made available by the HRZ (Lichtenberg-Cluster) at, TU Darmstadt. The authors would like to thank Prof. M. Heilmaier for scientific discussions. |
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