Journal of Materials Science

, Volume 50, Issue 8, pp 3149–3163 | Cite as

Pore connectivity of aluminium foams: effect of production parameters

  • J. LázaroEmail author
  • E. Solórzano
  • M. A. Rodríguez Pérez
  • F. García-Moreno
Original Paper


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.


Foam Cell Wall Thickness Aluminium Foam Crack Generation Thin Cell Wall 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



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.


  1. 1.
    Banhart J (2001) Manufacture, characterization and application of cellular metals. Prog Mater Sci 46(6):559–632CrossRefGoogle Scholar
  2. 2.
    Baumgärtner F, Duarte I, Banhart J (2000) Industrialization of powder compact foaming process. Adv Eng Mater 2:168–174CrossRefGoogle Scholar
  3. 3.
    Ito K, Kobayashi H (2006) Production and fabrication technology development of aluminum useful for automobile lightweighting. Adv Eng Mater 8:828–835CrossRefGoogle Scholar
  4. 4.
    Olurin OB, Fleck NA, Ashby MF (2000) Deformation and fracture of aluminium foams. Mater Sci Eng A 291:136–146CrossRefGoogle Scholar
  5. 5.
    Gibson LJ, Ashby MF (1997) Cellular solids: structure and properties, 2nd edn. Cambridge University Press, CambridgeCrossRefGoogle Scholar
  6. 6.
    McCullough KYG, Fleck NA, Ashby MF (1999) Toughness of aluminium alloy foam. Acta Mater 47:2331–2343CrossRefGoogle Scholar
  7. 7.
    Harte AM, Fleck NA, Ashby MF (1999) Fatigue failure of an open cell and closed cell Al foam. Acta Mater 47:2511–2524CrossRefGoogle Scholar
  8. 8.
    Gibson LJ (2000) Mechanical behaviour of metallic foams. Annu Rev Mater Sci 30:191–227CrossRefGoogle Scholar
  9. 9.
    Ramamurty U, Paul A (2004) Variability in the mechanical properties of a metal foam. Acta Mater 52:869–876CrossRefGoogle Scholar
  10. 10.
    Kennedy AR (2004) Aspects of the reproducibility of mechanical properties in Al based foams. J Mater Sci 39:3085–3088CrossRefGoogle Scholar
  11. 11.
    Nosko M, Simancik F, Florek R (2010) Reproducibility of aluminium foam properties: effect of precursor distribution on the structural anisotropy and the collapse stress and its dispersion. Mater Sci Eng A 527:5900–5908CrossRefGoogle Scholar
  12. 12.
    Evans AG, Sugimura Y (1997) On the mechanical performance of closed cell Al foam alloy. Acta Mater 45:5245–5259CrossRefGoogle Scholar
  13. 13.
    McCullough KYG, Fleck NA, Ashby MF (1999) Uniaxial stress-strain behaviour of aluminium foams. Acta Mater 47:2323–2330CrossRefGoogle Scholar
  14. 14.
    Grenestedt JL, Tanaka K (1999) Influence of cell shape variations on elastic stiffness of closed cellular solids. Scr Mater 40:71–77CrossRefGoogle Scholar
  15. 15.
    Banhart J, Baumeister J (1998) Deformation characteristics of metal foams. J Mater Sci 33:1431–1440CrossRefGoogle Scholar
  16. 16.
    Simone AE, Gibson LJ (1998) Effects of solid distribution on the stiffness and strength of metallica foams. Acta Mater 46(6):2139–2150CrossRefGoogle Scholar
  17. 17.
    Simone AE, Gibson LJ (1998) The effects of cell face curvature and corrugations on the stiffness and strength of metallica foams. Acta Mater 46(11):3929–3935CrossRefGoogle Scholar
  18. 18.
    Miyoshi T, Itoh M, Akiyama S, Kitahara A (2000) ALPORAS aluminium foam: production process, properties and applications. Adv Eng Mater 2(4):179–183CrossRefGoogle Scholar
  19. 19.
    Gergely V, Clyne TW (2000) The FORMGRIP process: foaming of reinforced metals by gas release in precursors. Adv Eng Mater 2:175–178CrossRefGoogle Scholar
  20. 20.
    Olurin OB, McCullough KYG, Fleck NA, Ashby MF (2001) Fatigue crack propagation in aluminium alloy foams. Int J Fatigue 23:375–382CrossRefGoogle Scholar
  21. 21.
    Banhart J, Schmoll C, Neuman U (1998) Light-weight aluminium foam structures for ships. In: Faria L (ed) Proceedings, vol 1. Sociedade Portuguesa de Materials, Lisbon, pp 55–63Google Scholar
  22. 22.
    Lu TJ, Hess A, Ashby MF (1999) Sound absorption in metallic foams. J Appl Phys 85(11):7528–7539CrossRefGoogle Scholar
  23. 23.
    Lu TJ, Chen F, He D (2000) Sound absorption of cellular metals with semi-open cells. J Acoust Soc Am 108:1697–1709CrossRefGoogle Scholar
  24. 24.
    Wang X, Lu TJ (1999) Optimized acoustic properties of cellular solids. J Acoust Soc Am 106(2):756–765CrossRefGoogle Scholar
  25. 25.
    Lu TJ, Chen C (1999) Thermal transport and fire retardance properties of cellular aluminium alloys. Acta Mater 47:1469–1485CrossRefGoogle Scholar
  26. 26.
    Lazaro J, Solorzano E, Escudero J, de Saja JA, Rodriguez-Perez MA (2012) Applicability of solid solution heat treatments to aluminium foams. Metals 2:508–528CrossRefGoogle Scholar
  27. 27.
    Elmouataouakkil A, Salvo L, Maire E, Peix G (2002) 2D and 3D characterization of metal foams using X-ray tomography. Adv Eng Mater 4:803–807CrossRefGoogle Scholar
  28. 28.
    Solorzano E, Rodriguez-Perez MA, de Saja JA (2008) Do we really produce closed cell metallic foams? In: Hirsch J, Skrotzki B, Gottstein G (eds) Proc of the ICAA-11, Wiley-VCH, Weinheim, pp 2200–2205Google Scholar
  29. 29.
    Lazaro J, Solorzano E, de Saja JA, Rodriguez-Perez MA (2013) Early anisotropic expansion of aluminium foam precursors. J Mater Sci 48:5036–5046CrossRefGoogle Scholar
  30. 30.
    Mukherjee M (2009) Evolution of metal foams during solidification. PhD Dissertation, Tech Univ, BerlinGoogle Scholar
  31. 31.
    Mukherjee M, Garcia-Moreno F, Banhart J (2007) Anomalous behaviour of aluminium foams during solidification. Trans Indian Inst Met 60:133–136Google Scholar
  32. 32.
    Mukherjee M, Garcia-Moreno F, Banhart J (2010) Solidification of aluminium foams. Acta Mater 58:6358–6370CrossRefGoogle Scholar
  33. 33.
    Mukherjee M, Garcia-Moreno F, Banhart J (2010) Defect generation during solidification of aluminium foams. Scr Mater 63:235–238CrossRefGoogle Scholar
  34. 34.
    Yu CJ, Eifert HH, Banhart J, Baumeister J (1998) Metal foaming by a powder metallurgical method: production, properties and applications. J Mater Res Innov 2:181–188CrossRefGoogle Scholar
  35. 35.
    Kennedy AR (2002) Effect of compaction density on foamability of Al-TiH2 powder compacts. Powder Metall 45:75–79CrossRefGoogle Scholar
  36. 36.
    Duarte I, Banhart J (2000) Influence of process parameters on the expansion behaviour of aluminium foams. In: Clyne TW, Simancik F (eds) Metal matrix composites and metallic foams. Wiley-VCH, Weinheim, pp 14–21Google Scholar
  37. 37.
    Asavavisithchai S, Kennedy AR (2006) The effect of compaction method on the expansion and stability of aluminium foams. Adv Eng Mater 8:810–815CrossRefGoogle Scholar
  38. 38.
    Youn SW, Kang CG (2004) Fabrication of foamable precursors by powder compression and induction heating process. Metall Mater Trans B 35:769–776CrossRefGoogle Scholar
  39. 39.
    Helwig HM, Hiller S, Garcia-Moreno F, Banhart J (2009) Influence of compaction conditions on the foamability of AlSi8Mg4 alloy. Metall Mater Trans B 40:755–767CrossRefGoogle Scholar
  40. 40.
    East J, Maxwell I (1985) Continuous extrusion of metals. US patent No. 4552520Google Scholar
  41. 41.
    Stauffer D (2003) Introduction to percolation theory. Taylor and Francis, London, pp 311–344Google Scholar
  42. 42.
    Solorzano E, Reglero JA, Rodriguez-Perez MA, de Saja JA, Rodriguez-Mendez ML (2007) Improvement of the foaming process for 4045 and 6061 aluminium foams by using the Taguchi methodology. J Mater Sci 42:7227–7238CrossRefGoogle Scholar
  43. 43.
    ASTM D6226-05 Standard test method for open-cell content of rigid cellular plastics by the air pycnometerGoogle Scholar
  44. 44.
    Cawood MJ (1980) A method for measuring the volume percentage of closed cells in rigid cellular plastics. Polym Test 1:283–285CrossRefGoogle Scholar
  45. 45.
    Solorzano E (2008) Aluminium foams: foaming process, structure and properties. PhD Dissertation, Univ ValladolidGoogle Scholar
  46. 46. Accessed 15 Oct 2014
  47. 47.
    Image Processing and Analysis in Java (ImageJ). Accessed 10 Apr 2014
  48. 48. Accessed 15 Oct 2014
  49. 49.
    Brabant L, Vlassenbroeck J et al (2011) Three-dimensional analysis of high-resolution X-ray computed tomography data with Morpho+. Microsc Microanal 17:252–263CrossRefGoogle Scholar
  50. 50.
    Solorzano E, Rodriguez-Perez MA, Reglero JA, de Saja JA (2007) Density gradients in aluminium foams: characterisation by computed tomography and measurements of the effective thermal conductivity. J Mater Sci 42:2557–2564CrossRefGoogle Scholar
  51. 51.
    Hildebrand T, Rüesgsegger P (1997) A new method for the model-independent assessment of thickness in three-dimensional images. J Microsc 185:67–75CrossRefGoogle Scholar
  52. 52.
    Garcia-Moreno F, Rack A et al (2008) Fast processes in liquid metal foams investigated by high-speed synchrotron X-ray micro-radioscopy. Appl Phys Lett 92(13):134104CrossRefGoogle Scholar
  53. 53.
    Rack A, Garcia-Moreno F, Baumbach T, Banhart J (2009) Synchrotron-based radioscopy employing spatio-temporal micro-resolution for studying fast phenomena in liquid metal foams. J Synch Radiat 16(3):432–434CrossRefGoogle Scholar
  54. 54.
    Anson JP, Gruzleski JE (1999) The quantitative discrimination between shrinkage and gas microporosity in cast aluminium alloys using spatial data analysis. Mater Charact 43:319–335CrossRefGoogle Scholar
  55. 55.
    Anson JP, Gruzleski JE (1999) Effect of hydrogen content on the relative amounts of shrinkage and gas microporosity in a cast Al-7 %Si foundry alloy. Trans Am Foundry Soc 107:135–142Google Scholar
  56. 56.
    Magnusson T, Arnberg L (2001) Density and solidification shrinkage of hypoeutectic aluminum-silicon alloys. Metall Mater Trans A 32(10):2605–2614CrossRefGoogle Scholar
  57. 57.
    Banhart J (2006) Metal foams: production and stability. Adv Eng Mater 8(9):781–794CrossRefGoogle Scholar
  58. 58.
    Toda H, Takata M et al (2006) 3-D Image-based mechanical simulation of aluminium foams: effects of internal microstructure. Adv Eng Mater 8(6):459–467CrossRefGoogle Scholar
  59. 59.
    Mukherjee M, Ramamurty U, Garcia-Moreno F, Banhart J (2010) The effect of cooling rate on structure and properties of closed-cell aluminium foams. Acta Mater 58:5031–5042CrossRefGoogle Scholar
  60. 60.
    Mutwil J, Kujawa K, Marczewski P, Michajlow P (2008) Influence of silicon concentration on linear contraction process of Al-Si binary alloy. Arch Foundry Eng 8(4):141–148Google Scholar
  61. 61.
    Keneddy AR, Lopez V (2003) The decomposition behaviour of as-received and oxidized TiH2. Mater Sci Eng A 357:258–263CrossRefGoogle Scholar
  62. 62.
    von Zeppelin F, Hirscher M, Stanzick H, Banhart J (2003) Desorption of hydrogen from blowing agents used for foaming metals. Compos Sci Technol 63:2293–2300CrossRefGoogle Scholar
  63. 63.
    Rack A, Helwig HM et al (2009) Early pore formation in aluminium foams studied with ex situ synchrotron micro-tomography and 3D image analysis. Acta Mater 57(16):4809–4821CrossRefGoogle Scholar
  64. 64.
    Lazaro J, Laguna-Gutierrez E, Solórzano E, Rodriguez-Perez MA (2013) Effect of microstructural anisotropy of PM precursor son the characteristic expansion of aluminium foams. Metall Mater Trans B 44:984–991CrossRefGoogle Scholar
  65. 65.
    Murray JL, McAlister AJ (1984) The Al-Si system. Bull Alloy Phase Diagr 5(1):74–84CrossRefGoogle Scholar
  66. 66.
    Raghavan V (2007) Al-Mg-Si. Phase diagrams evaluations 28:189–191Google Scholar
  67. 67.
    Lutze P, Ruge J (1990) Hydrogen in aluminium and its alloys. Metall 44:741–748Google Scholar

Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • J. Lázaro
    • 1
    Email author
  • E. Solórzano
    • 1
  • M. A. Rodríguez Pérez
    • 1
  • F. García-Moreno
    • 2
    • 3
  1. 1.Cellular Materials Laboratory (CellMat), Condensed Matter Physics Department, Science FacultyUniversity of ValladolidValladolidSpain
  2. 2.Helmholtz-Centre Berlin for Materials and EnergyBerlinGermany
  3. 3.Technical University Berlin, GermanyBerlinGermany

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