Herlach, Dieter M. (2014) Non-Equilibrium Solidification of Undercooled Metallic Melts. Metals (4), Seiten 196-234. Multidisciplinary Digital Publishing Institute (MDPI). doi: 10.3390/met4020196. ISSN 2075-4701.
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Offizielle URL: http://www.mdpi.com/jurnals/metals
Kurzfassung
An undercooled melt possesses an enhanced free enthalpy that enables to crystallize metastable solids in competition with their stable counterparts. Crystal nucleation selects the crystallographic phase whereas the growth dynamics controls microstructure evolution. We apply containerless processing such as electromagnetic and electrostatic levitation to containerlesss undercool and solidify metallic melts. Heterogeneous nucleation on container-walls is completely avoided leading to large undercooling with the extra benefit that the freely suspended drop is direct accessible for in situ observation of crystallization far away from equilibrium. Results of investigations of maximum undercoolability on pure zirconium are presented showing the limit of maximum undercoolability set by the onset of homogeneous nucleation. Rapid dendrite growth is measured as a function of undercooling by a high-speed camera and analysed within extended theories of non-equilibrium solidification. In such both supersaturated solid solutions and disordered superlattice structure of intermetallics are formed at high growth velocities. A sharp interface theory of dendrite growth is capable to describe the non-equilibrium solidification phenomena during rapid crystallization of deeply undercooled melts.
elib-URL des Eintrags: | https://elib.dlr.de/92394/ | ||||||||
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Dokumentart: | Zeitschriftenbeitrag | ||||||||
Titel: | Non-Equilibrium Solidification of Undercooled Metallic Melts | ||||||||
Autoren: |
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Datum: | 20 Juni 2014 | ||||||||
Erschienen in: | Metals | ||||||||
Referierte Publikation: | Ja | ||||||||
Open Access: | Ja | ||||||||
Gold Open Access: | Ja | ||||||||
In SCOPUS: | Nein | ||||||||
In ISI Web of Science: | Ja | ||||||||
DOI: | 10.3390/met4020196 | ||||||||
Seitenbereich: | Seiten 196-234 | ||||||||
Verlag: | Multidisciplinary Digital Publishing Institute (MDPI) | ||||||||
ISSN: | 2075-4701 | ||||||||
Status: | veröffentlicht | ||||||||
Stichwörter: | Undercooling, non-Equilibrium solidification, containerless processing, nucleation, growth kinetics, sharp interface theory | ||||||||
HGF - Forschungsbereich: | Luftfahrt, Raumfahrt und Verkehr | ||||||||
HGF - Programm: | Raumfahrt | ||||||||
HGF - Programmthema: | Forschung unter Weltraumbedingungen | ||||||||
DLR - Schwerpunkt: | Raumfahrt | ||||||||
DLR - Forschungsgebiet: | R FR - Forschung unter Weltraumbedingungen | ||||||||
DLR - Teilgebiet (Projekt, Vorhaben): | R - Vorhaben Materialwissenschaftliche Forschung (alt) | ||||||||
Standort: | Köln-Porz | ||||||||
Institute & Einrichtungen: | Institut für Materialphysik im Weltraum > Wissenschaftliche Experimente | ||||||||
Hinterlegt von: | Klein, Stefan | ||||||||
Hinterlegt am: | 25 Nov 2014 08:48 | ||||||||
Letzte Änderung: | 06 Nov 2023 14:17 |
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