A Numerical Study of the Influence of Pouring Technique on the As-Cast Structure of Al-Cu Ingots

Abstract:

Experimental evidence [Ohno 1987] revealed the influence of some pouring techniques on the as-cast structure. In the current work the process of pouring of the molten Al-4.0 wt.%Cu via one or multiple streams into a graphite mold is studied using a 3-phase model by considering the nucleation, the initial growth and transport of globular equiaxed crystals. The three phases are the melt, air and globular equiaxed crystals. Results showed that pouring via multiple streams increases the volume fraction and number density of crystals in the as-filled state. The subsequent solidification is calculated using a 5-phase mixed columnar-equiaxed solidification model. The five phases are the extradendritic melt, the solid dendrite and interdendritic melt inside the equiaxed grains, the solid dendrite and interdendritic melt inside the columnar grains. As final result the as-cast structure including the distinct columnar and equiaxed zones, columnar-to-equiaxed transition (CET), grain size, macrosegregation, and rest eutectic is predicted. Effect of melt convection and crystal sedimentation during the pouring and solidification is taken into account. The predicted as-cast structure, under the influence of single/multiple jet pouring, is evaluated bycomparison with the available experiments of Ohno.

• Periodical: Materials Science Forum (Volumes 790-791)
• Pages: 67-72
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.790-791.67
• Online since: May 2014
• Authors: Mahmoud Ahmadein*, Meng Huai Wu, Peter Schumacher, Andreas Ludwig
• Keywords: As-Cast Structure, Columnar-To-Equiaxed Transition, Macrosegregation, Modeling, Pouring, Solidification

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