On the production of high-porosity metallic solids
28 mins 55 secs,
420.79 MB,
MPEG-4 Video
640x360,
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44100 Hz,
1.94 Mbits/sec
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About this item
| Description: |
Stewart, P (University of Glasgow)
Thursday 26 June 2014, 10:50-11:20 |
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| Created: | 2014-07-11 13:54 |
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| Collection: | Free Boundary Problems and Related Topics |
| Publisher: | Isaac Newton Institute |
| Copyright: | Stewart, P |
| Language: | eng (English) |
| Distribution: |
World
(downloadable)
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| Explicit content: | No |
| Aspect Ratio: | 16:9 |
| Screencast: | No |
| Bumper: | UCS Default |
| Trailer: | UCS Default |
| Abstract: | Co-author: Stephen Davis (Northwestern University)
High-porosity metallic solids are useful as lightweight materials in many engineering disciplines. However, batch processing techniques for producing such materials by solidification of a molten metallic foam are problematic, and it is not currently possible to control the porosity distribution of the final product {\it a priori}. The molten metallic foam is inherently unstable; the thin liquid bridges between bubbles drain rapidly and rupture due to intermolecular forces, leading to bubble coalescence and large-scale topological rearrangement. In this talk we will consider the competition between coalesecence and freezing in these dynamically evolving foams, examining in particular the coupling between the microscale hydrodynamics in the molten liquid films and the progression of a solidification front. The foam is modelled as a coupled system of free boundary problems involving both liquid/gas and liquid/solid interfaces, which we solve using a combination of asymptotic and numerical techniques. An understanding of these microscale processes motivates other protocols for solid foam production where the porosity distribution of the final product can be more effectively controlled. |
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