Modeling of convection, temperature distribution and dendritic growth in glass-fluxed nickel melts / Gao Jianrong,Kao Andrew,Bojarevics Valdis,Pericleous Koulis,Galenko Peter K.,Alexandrov Dmitri V. // JOURNAL OF CRYSTAL GROWTH. - 2017. - V. 471, l. . - P. 66-72.

ISSN/EISSN:

0022-0248 / 1873-5002

Type:

Article

Abstract:

Melt flow is often quoted as the reason for a discrepancy between experiment and theory on dendritic growth kinetics at low undercoolings. But this flow effect is not justified for glass-fluxed melts where the flow field is weaker. In the present work, we modeled the thermal history, flow pattern and dendritic structure of a glass-fluxed nickel sample by magnetohydrodynamics calculations. First, the temperature distribution and flow structure in the molten and undercooled melt were simulated by reproducing the observed thermal history of the sample prior to solidification. Then the dendritic structure and surface temperature of the recalescing sample were simulated. These simulations revealed a large thermal gradient crossing the sample, which led to an underestimation of the real undercooling for dendritic growth in the bulk volume of the sample. By accounting for this underestimation, we recalculated the dendritic tip velocities in the glass-fluxed nickel melt using a theory of three-dimensional dendritic growth with convection and concluded an improved agreement between experiment and theory.

Author keywords:

Dendrites; Convection; Impurities; Solidification; Growth from melts; Metals

DOI:

10.1016/j.jcrysgro.2016.11.069

Web of Science ID:

ISI:000403624100010

Соавторы в МНС:

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Другие поля

Поле	Значение
Month	AUG 1
Publisher	ELSEVIER SCIENCE BV
Address	PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Language	English
EISSN	1873-5002
Research-Areas	Crystallography; Materials Science; Physics
Web-of-Science-Categories	Crystallography; Materials Science, Multidisciplinary; Physics, Applied
Author-Email	jgao@mail.neu.edu.cn
ORCID-Numbers	Gao, Jianrong/0000-0003-1160-6553
Funding-Acknowledgement	National Natural Science Foundation of China {[}51071043, 51211130113]; Fundamental Research Funds for Central Universities {[}N130509001]; Overseas Expert Program of the International Office of Northeastern University {[}X2015001]; International Exchanges Scheme of the Royal Society of the United Kingdom; Russian Science Foundation {[}16-11-10095]; German Research Foundation (DFG) {[}RE 1261/8-2]; Russian Foundation for Basic Research (RFBR) {[}14-29-10282]
Funding-Text	The authors thank S. Cai and Z. Thai for editing computer codes for calculations of dendritic tip velocities. J. Gao acknowledges support by the National Natural Science Foundation of China (51071043 and 51211130113), Fundamental Research Funds for Central Universities (N130509001), and the Overseas Expert Program of the International Office of Northeastern University (X2015001). A. Kao and K. Pericleous acknowledge support by the International Exchanges Scheme of the Royal Society of the United Kingdom. D. V. Alexandrov acknowledges support from the Russian Science Foundation (Project No. 16-11-10095). P. K. Galenko acknowledges support by German Research Foundation (DFG Project RE 1261/8-2) and Russian Foundation for Basic Research (RFBR Project No. 14-29-10282).
Number-of-Cited-References	18
Usage-Count-Last-180-days	3
Usage-Count-Since-2013	3
Journal-ISO	J. Cryst. Growth
Doc-Delivery-Number	EY0BV