Abstract
Samples from directionally solidified Al- 7 wt. % Si have been analyzed for primary dendrite arm spacing (A). The alloy was directionally solidified (DS) aboard the International Space Station (ISS) to determine the effect of mitigating convection on λ. In some experiments, λ was measured in microstructures that developed during the transition from one speed to another. To represent DS in the presence of no convection, the Hunt-Lu model was used to represent diffusion-controlled growth. By sectioning cross-sections throughout the entire length of a solidified sample, λ. was measured and calculated using the model. During steady state, there was reasonable agreement between the measured and calculated λ's in the space-grown samples. Where there was evidence of Marangoni convection, however, resulted in primary dendrite arm spacings that were larger than they would have been in the absence of convection.
Original language | English (US) |
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Title of host publication | Materials Science and Technology Conference and Exhibition 2015, MS and T 2015 |
Publisher | Association for Iron and Steel Technology, AISTECH |
Pages | 301-309 |
Number of pages | 9 |
Volume | 1 |
ISBN (Print) | 9781510813939 |
State | Published - 2015 |
Event | Materials Science and Technology Conference and Exhibition 2015, MS and T 2015 - Columbus, United States Duration: Oct 4 2015 → Oct 8 2015 |
Other
Other | Materials Science and Technology Conference and Exhibition 2015, MS and T 2015 |
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Country | United States |
City | Columbus |
Period | 10/4/15 → 10/8/15 |
Keywords
- Hunt and Lu model
- Microgravity
- Primary dendrite arm spacing
ASJC Scopus subject areas
- Materials Science (miscellaneous)
- Mechanics of Materials