Investigation of columnar-to-equiaxed transition in solidification processing of AlSi alloys in microgravity - The CETSOL project - Mines Paris
Communication Dans Un Congrès Année : 2011

Investigation of columnar-to-equiaxed transition in solidification processing of AlSi alloys in microgravity - The CETSOL project

Résumé

Grain structures observed in most casting processes of metallic alloys are the result of a competition between the growth of several arrays of dendrites that develop under constrained and unconstrained conditions. Often this leads to a transition from columnar to equiaxed grain growth during solidification (CET). A microgravity environment results in suppression of buoyancy-driven melt flow and so enables growth of equiaxed grains free of sedimentation and buoyancy effects. This contribution presents first results obtained in experiments on-board the International Space Station (ISS), which were performed in the frame of the ESA-MAP programme CETSOL. Hypoeutectic aluminium-silicon alloys with and without grain refiners were processed successfully in a low gradient furnace (MSL-LGF). First analysis shows that in the non grain refined samples columnar dendritic growth exists, whereas CET is observed in the grain refined samples. From analysis of the thermal data and the grain structure the critical parameters for the temperature gradient and the cooling rate describing CET are determined. These data are used for initial numerical simulations to predict the position of the columnar-to-equiaxed transition and will form a unique database for calibration and further development of numerical CET-modeling.

Domaines

Matériaux

Dates et versions

hal-00669349 , version 1 (13-02-2012)

Identifiants

Citer

Gerhard Zimmermann, Laszlo Sturz, Bernard Billia, Nathalie Mangelinck-Noel, H. Nguyen Thi, et al.. Investigation of columnar-to-equiaxed transition in solidification processing of AlSi alloys in microgravity - The CETSOL project. International Symposium on Physical Sciences in Space, Jul 2011, Bonn, Germany. pp.Article 012003, ⟨10.1088/1742-6596/327/1/012003⟩. ⟨hal-00669349⟩
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