Early Stages of Precipitation Process in Al-(Mn-)Sc-Zr Alloy Characterized by Positron Annihilation

Handle URI:
http://hdl.handle.net/10754/346766
Title:
Early Stages of Precipitation Process in Al-(Mn-)Sc-Zr Alloy Characterized by Positron Annihilation
Authors:
Vlach, Martin; Cizek, Jakub; Melikhova, Oksana; Stulikova, Ivana; Smola, Bohumil; Kekule, Tomas; Kudrnova, Hana; Gemma, Ryota; Neubert, Volkmar
Abstract:
Thermal effects on the precipitation stages in as-cast Al-0.70 at. pct Mn-0.15 at. pct Sc-0.05 at. pct Zr alloy were studied. The role of lattice defects was elucidated by positron annihilation spectroscopy (lifetime and coincidence Doppler broadening) enabling investigation of solutes clustering at the atomic scale. This technique has never been used in the Al-Sc- and/or Al-Zr-based alloys so far. Studies by positron annihilation were combined with resistometry, hardness measurements, and microstructure observations. Positrons trapped at defects are preferentially annihilated by Sc electrons. Lifetime of trapped positrons indicates that Sc atoms segregate at dislocations. Maximum fraction of positrons annihilated by Sc electrons occurring at 453 K (180 °C) suggests that clustering of Sc bound with vacancies takes place. It is followed by peak of this fraction at 573 K (300 °C). A rise of the contribution of trapped positrons annihilated by Zr electrons starting at 513 K (240 °C) and attaining maximum also at 573 K (300 °C) confirms that Zr participates in precipitation of the Al3Sc particles already at these temperatures. The pronounced hardening at 573 K (300 °C) has its nature in the precipitation of the Al3Sc particles with a Zr-rich shell. The contribution of trapped positrons annihilated by Mn electrons was found to be negligible. © 2015, The Minerals, Metals & Materials Society and ASM International.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Citation:
Early Stages of Precipitation Process in Al-(Mn-)Sc-Zr Alloy Characterized by Positron Annihilation 2015, 46 (4):1556 Metallurgical and Materials Transactions A
Publisher:
Springer Nature
Journal:
Metallurgical and Materials Transactions A
Issue Date:
29-Jan-2015
DOI:
10.1007/s11661-015-2767-x
Type:
Article
ISSN:
1073-5623; 1543-1940
Additional Links:
http://link.springer.com/10.1007/s11661-015-2767-x
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorVlach, Martinen
dc.contributor.authorCizek, Jakuben
dc.contributor.authorMelikhova, Oksanaen
dc.contributor.authorStulikova, Ivanaen
dc.contributor.authorSmola, Bohumilen
dc.contributor.authorKekule, Tomasen
dc.contributor.authorKudrnova, Hanaen
dc.contributor.authorGemma, Ryotaen
dc.contributor.authorNeubert, Volkmaren
dc.date.accessioned2015-03-17T13:20:08Zen
dc.date.available2015-03-17T13:20:08Zen
dc.date.issued2015-01-29en
dc.identifier.citationEarly Stages of Precipitation Process in Al-(Mn-)Sc-Zr Alloy Characterized by Positron Annihilation 2015, 46 (4):1556 Metallurgical and Materials Transactions Aen
dc.identifier.issn1073-5623en
dc.identifier.issn1543-1940en
dc.identifier.doi10.1007/s11661-015-2767-xen
dc.identifier.urihttp://hdl.handle.net/10754/346766en
dc.description.abstractThermal effects on the precipitation stages in as-cast Al-0.70 at. pct Mn-0.15 at. pct Sc-0.05 at. pct Zr alloy were studied. The role of lattice defects was elucidated by positron annihilation spectroscopy (lifetime and coincidence Doppler broadening) enabling investigation of solutes clustering at the atomic scale. This technique has never been used in the Al-Sc- and/or Al-Zr-based alloys so far. Studies by positron annihilation were combined with resistometry, hardness measurements, and microstructure observations. Positrons trapped at defects are preferentially annihilated by Sc electrons. Lifetime of trapped positrons indicates that Sc atoms segregate at dislocations. Maximum fraction of positrons annihilated by Sc electrons occurring at 453 K (180 °C) suggests that clustering of Sc bound with vacancies takes place. It is followed by peak of this fraction at 573 K (300 °C). A rise of the contribution of trapped positrons annihilated by Zr electrons starting at 513 K (240 °C) and attaining maximum also at 573 K (300 °C) confirms that Zr participates in precipitation of the Al3Sc particles already at these temperatures. The pronounced hardening at 573 K (300 °C) has its nature in the precipitation of the Al3Sc particles with a Zr-rich shell. The contribution of trapped positrons annihilated by Mn electrons was found to be negligible. © 2015, The Minerals, Metals & Materials Society and ASM International.en
dc.publisherSpringer Natureen
dc.relation.urlhttp://link.springer.com/10.1007/s11661-015-2767-xen
dc.rightsArchived with thanks to Metallurgical and Materials Transactions Aen
dc.titleEarly Stages of Precipitation Process in Al-(Mn-)Sc-Zr Alloy Characterized by Positron Annihilationen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalMetallurgical and Materials Transactions Aen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionFaculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 121 16, Prague, Czech Republicen
dc.contributor.institutionInstitut für Materialprüfung und Werkstofftechnik, Freiberger Strasse 1, 38678, Clausthal-Zellerfeld, Germanyen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorGemma, Ryotaen
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