Growth of lamellar eutectic dendrites in undercooled melts

Goetzinger, R. ; Barth, M. ; Herlach, D. M.

[S.l.] : American Institute of Physics (AIP)
Published 1998
ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Electromagnetic levitation is used to undercool bulk samples of eutectic Ni 21.4 at % Si alloys. Large undercoolings ΔT up to ΔT=220 K are achieved by containerless processing of the melts. Crystal growth velocities are measured as a function of undercooling. The growth kinetics during solidification of the eutectic alloys is controlled by atomic diffusion. A maximum in the relation of the growth velocity on undercooling is observed which is due to the progressively decreasing diffusion coefficient counteracting the enhancement of the driving force of crystallization with increasing undercooling. Microstructure analysis of as-solidified samples reveals colonies of eutectic lamellae enveloped by a nonplanar growth front of a dendritelike morphology. The experimental data are analyzed within current models of crystal growth taking into account a negative temperature gradient in front of the solidification front. While the thermal undercooling causes a dendriticlike morphology of the solidification front, constitutional and curvature undercooling control the formation of the eutectic colonies behind it. © 1998 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
_version_ 1798289639421771778
autor Goetzinger, R.
Barth, M.
Herlach, D. M.
autorsonst Goetzinger, R.
Barth, M.
Herlach, D. M.
book_url http://dx.doi.org/10.1063/1.368233
datenlieferant nat_lic_papers
hauptsatz hsatz_simple
identnr NLZ218446802
issn 1089-7550
journal_name Journal of Applied Physics
materialart 1
notes Electromagnetic levitation is used to undercool bulk samples of eutectic Ni 21.4 at % Si alloys. Large undercoolings ΔT up to ΔT=220 K are achieved by containerless processing of the melts. Crystal growth velocities are measured as a function of undercooling. The growth kinetics during solidification of the eutectic alloys is controlled by atomic diffusion. A maximum in the relation of the growth velocity on undercooling is observed which is due to the progressively decreasing diffusion coefficient counteracting the enhancement of the driving force of crystallization with increasing undercooling. Microstructure analysis of as-solidified samples reveals colonies of eutectic lamellae enveloped by a nonplanar growth front of a dendritelike morphology. The experimental data are analyzed within current models of crystal growth taking into account a negative temperature gradient in front of the solidification front. While the thermal undercooling causes a dendriticlike morphology of the solidification front, constitutional and curvature undercooling control the formation of the eutectic colonies behind it. © 1998 American Institute of Physics.
package_name American Institute of Physics (AIP)
publikationsjahr_anzeige 1998
publikationsjahr_facette 1998
publikationsjahr_intervall 8004:1995-1999
publikationsjahr_sort 1998
publikationsort [S.l.]
publisher American Institute of Physics (AIP)
reference 84 (1998), S. 1643-1649
search_space articles
shingle_author_1 Goetzinger, R.
Barth, M.
Herlach, D. M.
shingle_author_2 Goetzinger, R.
Barth, M.
Herlach, D. M.
shingle_author_3 Goetzinger, R.
Barth, M.
Herlach, D. M.
shingle_author_4 Goetzinger, R.
Barth, M.
Herlach, D. M.
shingle_catch_all_1 Goetzinger, R.
Barth, M.
Herlach, D. M.
Growth of lamellar eutectic dendrites in undercooled melts
Electromagnetic levitation is used to undercool bulk samples of eutectic Ni 21.4 at % Si alloys. Large undercoolings ΔT up to ΔT=220 K are achieved by containerless processing of the melts. Crystal growth velocities are measured as a function of undercooling. The growth kinetics during solidification of the eutectic alloys is controlled by atomic diffusion. A maximum in the relation of the growth velocity on undercooling is observed which is due to the progressively decreasing diffusion coefficient counteracting the enhancement of the driving force of crystallization with increasing undercooling. Microstructure analysis of as-solidified samples reveals colonies of eutectic lamellae enveloped by a nonplanar growth front of a dendritelike morphology. The experimental data are analyzed within current models of crystal growth taking into account a negative temperature gradient in front of the solidification front. While the thermal undercooling causes a dendriticlike morphology of the solidification front, constitutional and curvature undercooling control the formation of the eutectic colonies behind it. © 1998 American Institute of Physics.
1089-7550
10897550
American Institute of Physics (AIP)
shingle_catch_all_2 Goetzinger, R.
Barth, M.
Herlach, D. M.
Growth of lamellar eutectic dendrites in undercooled melts
Electromagnetic levitation is used to undercool bulk samples of eutectic Ni 21.4 at % Si alloys. Large undercoolings ΔT up to ΔT=220 K are achieved by containerless processing of the melts. Crystal growth velocities are measured as a function of undercooling. The growth kinetics during solidification of the eutectic alloys is controlled by atomic diffusion. A maximum in the relation of the growth velocity on undercooling is observed which is due to the progressively decreasing diffusion coefficient counteracting the enhancement of the driving force of crystallization with increasing undercooling. Microstructure analysis of as-solidified samples reveals colonies of eutectic lamellae enveloped by a nonplanar growth front of a dendritelike morphology. The experimental data are analyzed within current models of crystal growth taking into account a negative temperature gradient in front of the solidification front. While the thermal undercooling causes a dendriticlike morphology of the solidification front, constitutional and curvature undercooling control the formation of the eutectic colonies behind it. © 1998 American Institute of Physics.
1089-7550
10897550
American Institute of Physics (AIP)
shingle_catch_all_3 Goetzinger, R.
Barth, M.
Herlach, D. M.
Growth of lamellar eutectic dendrites in undercooled melts
Electromagnetic levitation is used to undercool bulk samples of eutectic Ni 21.4 at % Si alloys. Large undercoolings ΔT up to ΔT=220 K are achieved by containerless processing of the melts. Crystal growth velocities are measured as a function of undercooling. The growth kinetics during solidification of the eutectic alloys is controlled by atomic diffusion. A maximum in the relation of the growth velocity on undercooling is observed which is due to the progressively decreasing diffusion coefficient counteracting the enhancement of the driving force of crystallization with increasing undercooling. Microstructure analysis of as-solidified samples reveals colonies of eutectic lamellae enveloped by a nonplanar growth front of a dendritelike morphology. The experimental data are analyzed within current models of crystal growth taking into account a negative temperature gradient in front of the solidification front. While the thermal undercooling causes a dendriticlike morphology of the solidification front, constitutional and curvature undercooling control the formation of the eutectic colonies behind it. © 1998 American Institute of Physics.
1089-7550
10897550
American Institute of Physics (AIP)
shingle_catch_all_4 Goetzinger, R.
Barth, M.
Herlach, D. M.
Growth of lamellar eutectic dendrites in undercooled melts
Electromagnetic levitation is used to undercool bulk samples of eutectic Ni 21.4 at % Si alloys. Large undercoolings ΔT up to ΔT=220 K are achieved by containerless processing of the melts. Crystal growth velocities are measured as a function of undercooling. The growth kinetics during solidification of the eutectic alloys is controlled by atomic diffusion. A maximum in the relation of the growth velocity on undercooling is observed which is due to the progressively decreasing diffusion coefficient counteracting the enhancement of the driving force of crystallization with increasing undercooling. Microstructure analysis of as-solidified samples reveals colonies of eutectic lamellae enveloped by a nonplanar growth front of a dendritelike morphology. The experimental data are analyzed within current models of crystal growth taking into account a negative temperature gradient in front of the solidification front. While the thermal undercooling causes a dendriticlike morphology of the solidification front, constitutional and curvature undercooling control the formation of the eutectic colonies behind it. © 1998 American Institute of Physics.
1089-7550
10897550
American Institute of Physics (AIP)
shingle_title_1 Growth of lamellar eutectic dendrites in undercooled melts
shingle_title_2 Growth of lamellar eutectic dendrites in undercooled melts
shingle_title_3 Growth of lamellar eutectic dendrites in undercooled melts
shingle_title_4 Growth of lamellar eutectic dendrites in undercooled melts
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source_archive AIP Digital Archive
timestamp 2024-05-06T08:04:02.497Z
titel Growth of lamellar eutectic dendrites in undercooled melts
titel_suche Growth of lamellar eutectic dendrites in undercooled melts
topic U
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