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Microstructure and macrosegregation study of directionally solidified al-7si samples processed terrestrially and aboard the international space station
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Grugel, R. N. Angart, Samuel Poirier, David R. Erdman, R. G. Tewari, S. N. |
| Copyright Year | 2014 |
| Description | This talk reports research that has been carried out under the aegis of NASA as part of a collaboration between ESA and NASA for solidification experiments on the International Space Station (ISS). The focus has been on the effect of convection on the microstructural evolution and macrosegregation in hypoeutectic AlâSi alloys during directional solidification (DS). The DSâexperiments have been carried out under 1âg at Cleveland State University (CSU) and under lowâg on the International Space Station (ISS). The thermal processingâhistory of the experiments is well defined for both the terrestriallyâprocessed samples and the ISSâprocessed samples. We have observed that the primary dendrite arm spacings of two samples grown in the lowâg environment of the ISS show good agreement with a dendriteâgrowth model based on diffusion controlled growth. The gravityâdriven convection (i.e., thermosolutal convection) in terrestrially grown samples has the effect of decreasing the primary dendrite arm spacings and causes macrosgregation. In order to process DSâsamples aboard the ISS, dendriticâseed crystals have to partially remelted in a stationary thermal gradient before the DS is carried out. Microstructural changes and macrosegregation effects during this period are described. |
| File Size | 77571 |
| Page Count | 1 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20140016705 |
| Archival Resource Key | ark:/13960/t2q57m49t |
| Language | English |
| Publisher Date | 2014-10-05 |
| Access Restriction | Open |
| Subject Keyword | Space Processing Directional Solidification Crystals Separation Laboratories Spaceborne Experiments Aluminum Alloys Free Convection Silicon Alloys International Space Station European Space Agency Comparison Melts Crystal Growth Eutectic Alloys Microstructure Microgravity Crystal Structure Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
