Coarsening evolution of dendritic sidearms: From synchrotron experiments to quantitative modeling

H Neumann-Heyme; N Shevchenko; Z Lei; K Eckert; O Keplinger; J Grenzer; C Beckermann; S Eckert

doi:10.1016/j.actamat.2017.12.056

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Coarsening evolution of dendritic sidearms: From synchrotron experiments to quantitative modeling

Journal article

Peer reviewed

Coarsening evolution of dendritic sidearms: From synchrotron experiments to quantitative modeling

H Neumann-Heyme, N Shevchenko, Z Lei, K Eckert, O Keplinger, J Grenzer, C Beckermann and S Eckert

Acta materialia, Vol.146, pp.176-186

03/2018

DOI: 10.1016/j.actamat.2017.12.056

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Abstract

The local dynamics of dendritic sidearms during coarsening are studied by combining in-situ radiography observations with numerical and analytical models. A flat sample of a Ga-In alloy is partially solidified and then held isothermally in a vertical temperature gradient. The evolving dendritic microstructure is visualized using synchrotron X-ray imaging at the BM20 (ROBL) beamline at ESRF, France. During the coarsening stage, the temporal evolution of the geometrical features of sidebranches is captured by automated image processing. This data is then used to quantify the dynamics of two basic evolution mechanisms for sidebranches: retraction and pinch-off. The universal dynamics of sidearm necks during pinch-off are exploited to determine the product of liquid diffusivity and capillarity length Dd0, as a parameter that is crucial in the calibration of quantitative models. By employing an idealized phase-field model for the evolution of a single sidebranch, the behavior of selected sidebranches is reproduced from the experiments in a consistent way. [Display omitted]

Coarsening

Dendritic solidification

Material properties

Microstructure

Phase-field model

Sidearm detachment

X-ray radiography

Details

Title: Subtitle: Coarsening evolution of dendritic sidearms: From synchrotron experiments to quantitative modeling
Creators: H Neumann-Heyme - Helmholtz-Zentrum Dresden-Rossendorf
N Shevchenko - Helmholtz-Zentrum Dresden-Rossendorf
Z Lei - Technische Universität Dresden
K Eckert - Technische Universität Dresden
O Keplinger - Helmholtz-Zentrum Dresden-Rossendorf
J Grenzer - Helmholtz-Zentrum Dresden-Rossendorf
C Beckermann - University of Iowa
S Eckert - Helmholtz-Zentrum Dresden-Rossendorf
Resource Type: Journal article
Publication Details: Acta materialia, Vol.146, pp.176-186
DOI: 10.1016/j.actamat.2017.12.056
ISSN: 1359-6454
eISSN: 1873-2453
Publisher: Elsevier Ltd
Grant note: name: German Helmholtz Association; DOI: 10.13039/100000104, name: NASA, award: NNX14AD69G
Language: English
Date published: 03/2018
Academic Unit: Mechanical Engineering
Record Identifier: 9984196614002771

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