elib
DLR-Header
DLR-Logo -> http://www.dlr.de
DLR Portal Home | Impressum | Kontakt | English
Schriftgröße: [-] Text [+]

New evidence for the dual origin of anomalous eutectic structures in undercooled Ni–Sn alloys: In situ observations and EBSD characterization

Yang, C. und Gao, Jianrong und Zhank, Yikun und Kolbe, Matthias und Herlach, Dieter M. (2011) New evidence for the dual origin of anomalous eutectic structures in undercooled Ni–Sn alloys: In situ observations and EBSD characterization. Acta Materialia, 59, Seiten 3915-3926. DOI: 10.1016/j.actamat.2011.03.016.

Dieses Archiv kann nicht den gesamten Text zur Verfügung stellen.

Kurzfassung

Rapid solidification processes of glass-fluxed Ni81.3Sn18.7 eutectic alloys at various undercoolings were observed in situ using a highspeed camera. The microstructure of the samples was characterized using optical microscopy, scanning electron microscopy and electron back-scattering diffraction analysis. It was found that the recalescence front sweeps the sample surface from one side to the other, which coincides with the formation of a directional solidification microstructure. Such a finding suggests that it is feasible to measure crystal growth velocities in the undercooled liquid by tracking the loci of the recalescence front. The measured data show sudden acceleration of crystal growth kinetics at a medium undercooling, giving evidence for a transition from coupled growth to uncoupled growth. Microscopic studies revealed that the sample with an undercooling of 202 K comprises two types of anomalous eutectic, which are distinguished by the size and orientations of Ni-rich grains. The results verify a recent hypothesis that anomalous eutectic in undercooled Ni–Sn alloys has a dual origin: it results from eutectic dendrites growing at low undercoolings and from single-phase Ni-rich dendrites growing at high undercoolings.

Dokumentart:Zeitschriftenbeitrag
Titel:New evidence for the dual origin of anomalous eutectic structures in undercooled Ni–Sn alloys: In situ observations and EBSD characterization
Autoren:
AutorenInstitution oder E-Mail-Adresse der Autoren
Yang, C.Northeastern University Shenyang
Gao, JianrongNortheastern University Shenyang
Zhank, YikunNortheastern University Shenyang
Kolbe, Matthiasmatthias.kolbe@dlr.de
Herlach, Dieter M.dieter.herlach@dlr.de
Datum:26 April 2011
Erschienen in:Acta Materialia
Referierte Publikation:Ja
In Open Access:Nein
In SCOPUS:Ja
In ISI Web of Science:Ja
Band:59
DOI :10.1016/j.actamat.2011.03.016
Seitenbereich:Seiten 3915-3926
Status:veröffentlicht
Stichwörter:Undercooling, non-equilibrium solidification, eutectic growth, eutectic microstructures
HGF - Forschungsbereich:Verkehr und Weltraum (alt)
HGF - Programm:Weltraum (alt)
HGF - Programmthema:W FR - Forschung unter Weltraumbedingungen (alt)
DLR - Schwerpunkt:Weltraum
DLR - Forschungsgebiet:W FR - Forschung unter Weltraumbedingungen
DLR - Teilgebiet (Projekt, Vorhaben):W - Vorhaben Materialwissenschaftliche Forschung (alt)
Standort: Köln-Porz
Institute & Einrichtungen:Institut für Materialphysik im Weltraum
Hinterlegt von: Dieter Herlach
Hinterlegt am:02 Mai 2011 09:50
Letzte Änderung:26 Mär 2013 13:28

Nur für Mitarbeiter des Archivs: Kontrollseite des Eintrags

Blättern
Suchen
Hilfe & Kontakt
Informationen
electronic library verwendet EPrints 3.3.12
Copyright © 2008-2013 Deutsches Zentrum für Luft- und Raumfahrt (DLR). Alle Rechte vorbehalten.