Modeling Macrosegregation in Directionally Solidified Aluminum Alloys under Gravitational and Microgravitational Conditions

Technical Report · Mon Sep 01 00:00:00 EDT 2014

DOI:https://doi.org/10.2172/1433070· OSTI ID:1433070

Lauer, Mark A. ^[1]; Poirier, David R. ^[1]; Erdmann, Robert G. ^[1]; Tewari, Surendra N. ^[2]; Madison, Jonathan D ^[3]

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1. The Univ. of Arizona, Tucson, AZ (United States)
2. Cleveland State Univ., Cleveland, OH (United States)
3. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

This report covers the modeling of seven directionally solidified samples, five under normal gravitational conditions and two in microgravity. A model is presented to predict macrosegregation during the melting phases of samples solidified under microgravitational conditions. The results of this model are compared against two samples processed in microgravity and good agreement is found. A second model is presented that captures thermosolutal convection during directional solidification. Results for this model are compared across several experiments and quantitative comparisons are made between the model and the experimentally obtained radial macrosegregation profiles with good agreement being found. Changes in cross section were present in some samples and micrographs of these are qualitatively compared with the results of the simulations. It is found that macrosegregation patterns can be affected by changing the mold material.

• Research Organization: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: National Aeronautics and Space Administration (NASA); USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 1433070
• Report Number(s): SAND-2014-17638; 662153
• Country of Publication: United States
• Language: English