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MM: Metall- und Materialphysik

MM 18: Materials Design

MM 18.5: Vortrag

Dienstag, 28. März 2006, 15:45–16:00, IFW B

The evolution of the structure of liquid aluminium foams: comparison between in-situ X-ray observations and numerical calculations. — •Oliver Brunke and Stefan Odenbach — TU Dresden, Professur für Magnetofluiddynamik, 01062 Dresden

Drainage is one of the driving forces for the temporal instability of liquid metal foams. For usual aqueous foams this phenomenon is very well examined and understood on both, the experimental as well the theoretical side. The situation is different for metallic foams. Due to their opaque nature, the observation of drainage is just possible by either measuring the density distribution of solidified samples ex-situ, or by x-ray or neutron radioscopy. We will report on the drainage behaviour of Al foams grown by a powder-metallurgical production route. The changes of the structure during the ageing of the foam have been observed in-situ by means of a tabletop x-ray radioscopy system. This method allows us to get direct information about the temporal density redistribution and therefore the drainage behaviour of liquid metallic foams. A direct comparison of the experimental data to numerical results obtained by solving the foam drainage equation shows that this theory, which has proved to be successful for the theoretical description of aqueous foams, can in principle also be used to model the material redistribution in metallic foams.