Pore connectivity of aluminium foams: effect of production parameters

Abstract

This work studies the effect of some production parameters on the pore connectivity grade (i.e., the open-cell content associated cracks and missing cell walls) of aluminium foams produced via powder metallurgy route. Two types of precursors, extruded and hot uniaxially compressed, were used to create a varied group of Al–Si and Al–Si-Mg alloy-based foams in a wide porosity range. The cellular structure and defects were characterized by gas pycnometry and X-ray tomography. The analysis performed points to a high pore connectivity in all foam specimens, despite these materials are classified as closed celled due to their appearance, and a significant dependence on all the parameters varied. These dependences and the related mechanisms are discussed in the paper in terms of (i) the dissimilar foam evolution at initial stages (effect of precursor processing technique), (ii) the solidification shrinkage of each alloy (effect of composition) and (iii) the cell wall thinning (effect of foam porosity and local drainage). In addition, it has been observed that the interconnections are preferably located in the central parts of the samples, thus suggesting the possible effect of the cooling conditions on defect generation.

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Acknowledgements

Financial assistance the Spanish Ministry of Science and Innovation and FEDER (MAT2009-14001-C02-01 and MAT2012-34901) and of the ESA (AO-99-075) is gratefully acknowledged. In addition, authors are grateful to the Spanish Ministry of Science and Education which supported this investigation with a FPU-doctoral grant Ref-AP-2007-03318 (Jaime Lázaro) and Juan de la Cierva grant JCI-2011-09775 (Eusebio Solórzano). Authors would also like to thank Alulight Company for having provided some of the precursor materials used in this study.

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Lázaro, J., Solórzano, E., Rodríguez Pérez, M.A. et al. Pore connectivity of aluminium foams: effect of production parameters. J Mater Sci 50, 3149–3163 (2015). https://doi.org/10.1007/s10853-015-8876-5

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Keywords

  • Foam
  • Cell Wall Thickness
  • Aluminium Foam
  • Crack Generation
  • Thin Cell Wall