Characterization of the Al-3wt.%Si alloy in unsteady-state horizontal directional solidification

Materials Research

Diego Brito Carvalho²  Emanuelle Casseb Guimarães²  Antonio Luciano Moreira²  Daniel Joaquim Moutinho²  José Marcelino Dias Filho¹  Otávio Lima Da Rocha¹ 

[1] ,Federal University of Pará Faculty of Mechanical Engineering Belém PA ,Brazil

关键词: columnar to equiaxed transition;    primary dendritic spacing;    directional solidification;    unsteady-state conditions;    Al-Si alloys;   

DOI  :  10.1590/S1516-14392013005000072

来源: SciELO

【 摘 要 】

The main purpose of this paper is to investigate both the columnar to equiaxed transition and primary dendritic arm spacings of Al-3wt.%Si alloy during the horizontal directional solidification. The transient heat transfer coefficient at the metal-mold interface is calculated based on comparisons between the experimental thermal profiles in castings and the simulations provided by a finite difference heat flow program. Simulated curve of the interfacial heat transfer coefficient was used in another numerical solidification model to determine theoretical values of tip growth rates, cooling rates and thermal gradients that are associated with both columnar to equiaxed transition and primary dendritic arm spacings. A good agreement was observed between the experimental values of these thermal variables and those numerically simulated for the alloy examined. A comparative analysis is carried out between the experimental data of this work and theoretical models from the literature that have been proposed to predict the primary dendritic spacings. In this context, this study may contribute to the understanding of how to manage solidification operational parameters aiming at designing the microstructure of Al-Si alloys.

【 授权许可】

CC BY   
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