Journal article
Columnar and Equiaxed Solidification of Al-7 wt.% Si Alloys in Reduced Gravity in the Framework of the CETSOL Project
JOM (1989), Vol.69(8), pp.1269–1279-1279
08/2017
DOI: 10.1007/s11837-017-2397-4
Abstract
During casting, often a dendritic microstructure is formed, resulting in a columnar or an equiaxed grain structure, or leading to a transition from columnar to equiaxed growth (CET). The detailed knowledge of the critical parameters for the CET is important because the microstructure affects materials properties. To provide unique data for testing of fundamental theories of grain and microstructure formation, solidification experiments in microgravity environment were performed within the European Space Agency Microgravity Application Promotion (ESA MAP) project Columnar-to-Equiaxed Transition in SOLidification Processing (CETSOL). Reduced gravity allows for purely diffusive solidification conditions, i.e., suppressing melt flow and sedimentation and floatation effects. On-board the International Space Station, Al-7 wt.% Si alloys with and without grain refiners were solidified in different temperature gradients and with different cooling conditions. Detailed analysis of the microstructure and the grain structure showed purely columnar growth for nonrefined alloys. The CET was detected only for refined alloys, either as a sharp CET in the case of a sudden increase in the solidification velocity or as a progressive CET in the case of a continuous decrease of the temperature gradient. The present experimental data were used for numerical modeling of the CET with three different approaches: (1) a front tracking model using an equiaxed growth model, (2) a three-dimensional (3D) cellular automaton–finite element model, and (3) a 3D dendrite needle network method. Each model allows for predicting the columnar dendrite tip undercooling and the growth rate with respect to time. Furthermore, the positions of CET and the spatial extent of the CET, being sharp or progressive, are in reasonably good quantitative agreement with experimental measurements.
Details
- Title: Subtitle
- Columnar and Equiaxed Solidification of Al-7 wt.% Si Alloys in Reduced Gravity in the Framework of the CETSOL Project
- Creators
- Gerhard Zimmermann - AccessLaszlo Sturz - AccessHenri Nguyen-Thi - Institut des Matériaux, de Microélectronique et des Nanosciences de ProvenceNathalie Mangelinck-Noël - Institut des Matériaux, de Microélectronique et des Nanosciences de ProvenceY. Z Li - Institut des Matériaux, de Microélectronique et des Nanosciences de ProvenceCharles-André Gandin - Centre de Mise en Forme des MatériauxRomain Fleurisson - Centre de Mise en Forme des MatériauxGildas Guillemot - Centre de Mise en Forme des MatériauxShaun Mcfadden - Trinity College DublinRobin Patrick Mooney - Trinity College DublinPeter W Voorhees - Northwestern UniversityAndrás Roósz - University of MiskolcArnold Rónaföldi - University of MiskolcChristoph Beckermann - University of IowaAlain Karma - Northeastern UniversityC.-H Chen - Northeastern UniversityNils Warnken - University of BirminghamAli Saad - Transvalor (France)Gerd-Ulrich Grün - Hydro Aluminium Deutschland GmbH, R&D Center BonnM Grohn - Incaal GmbHIsabelle Poitrault - ArcelorMittalTibor Pehl - Arconic-Köfém LtdI Nagy - INOTAL AluminiumfeldolgozoD Todt - NEMAK Györ Kft.Olivier Minster - European Space Research and Technology CentreWim H Sillekens - European Space Research and Technology Centre
- Resource Type
- Journal article
- Publication Details
- JOM (1989), Vol.69(8), pp.1269–1279-1279
- DOI
- 10.1007/s11837-017-2397-4
- ISSN
- 1047-4838
- eISSN
- 1543-1851
- Publisher
- Springer Verlag (Germany)
- Language
- English
- Date published
- 08/2017
- Academic Unit
- Mechanical Engineering
- Record Identifier
- 9984196522902771
Metrics
25 Record Views