Skip to main content
Log in

Production and properties of a precision-cast bio-inspired composite

  • Published:
Journal of Materials Science Aims and scope Submit manuscript


The article presents the production and investigation of a bio-inspired metal–metal-composite inspired by the pomelo peel. The pomelo fruit is able to withstand a fall externally undamaged, even from heights of over 10 m most likely due to the hierarchical structuring of its foamy peel, which represents a complex composite structure. Especially the foam’s struts, which are cells from the biological point of view, consisting of liquid-filled cores and shells (cell walls) with relatively high strength, give point to a technical adaptation. With the objective to make use of the pomelo’s ability to absorb impact energy, the design of a pomelo strut is abstracted and transferred to aluminium/aluminium–silicon-alloy (A356) composite tensile specimens. Testing results show that the properties of the individual materials can successfully be combined. After fracture of the outer high strength, but less ductile A356-shell, the applied stress can still be absorbed by deformation of the inner highly ductile pure aluminium. As a result, the ductility of a bio-inspired composite is significantly higher compared with an A356 tensile specimen. By varying the mould and casting temperatures, the relationship between the production parameters and the quality of the composite is shown. A reduced mould and casting temperature lowers the dendrite arm spacing in the A356 outer shell of the composite material thus leading to an increased tensile strength. The detected metal bond between the two materials is mainly influenced by the interaction between the casting and the mould temperature.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9

Similar content being viewed by others


  1. Kromm FX, Quenisset JM, Harry R, Lorriot T (2002) An example of multimaterials design. Adv Eng Mater 4(6):371–374

    Article  Google Scholar 

  2. Ashby MF, Bréchet YJM (2003) Designing hybrid materials. Acta Mater 51(19):5801–5821

    Article  CAS  Google Scholar 

  3. Munch E, Launey ME, Alsem DH, Saiz E, Tomsia A, Ritchie RO (2008) Tough, Bio-inspired hybrid materials. Science 322(5):1516–1520

    Article  PubMed  CAS  ADS  Google Scholar 

  4. Bian L, Liang W, Xie G, Zhang W, Xue J (2011) Enhanced ductility in an Al–Mg2Si in situ composite processed by ECAP using a modified BC route. Mater Sci Eng, A 528(9):3463–3467

    Article  Google Scholar 

  5. Sirisalee P, Ashby MF, Parks GT, Clarkson PJ (2006) Multi-criteria material selection of monolithic and multi-materials in engineering design. Adv Eng Mater 8(1–2):48–56

    Article  Google Scholar 

  6. Cluff DRA, Esmaeili S (2009) Compressive properties of a new metal-polymer hybrid material. J Mater Sci. doi:10.1007/s10853-009-3525-5

    Google Scholar 

  7. Akdemir A, Kus R, Simsir M (2011) Investigation of the tensile properties of continuous steel wire-reinforced gray cast iron composite. Mater Sci Eng A 528(10–11):3897–3904

    Article  Google Scholar 

  8. Dunlop JWC, Fratzl P (2013) Multilevel architectures in natural materials. Scripta Mater 68:8–12

    Article  CAS  Google Scholar 

  9. Aizenberg J, Weaver JC, Thanawala MS, Sundar VC, Morse DE, Fratzl P (2005) Skeleton of Euplectella sp.: structural hierarchy from the nanoscale to the macroscale. Science 309(8):275–278

    Article  PubMed  CAS  ADS  Google Scholar 

  10. Woesz A, Weaver JC, Kazanci M, Dauphin Y, Aizenberg J, Morse DE, Fratzl P (2006) Micromechanical properties of biological silica in skeletons of deep-sea sponges. J Mater Res 21(8):2068–2078

    Article  CAS  ADS  Google Scholar 

  11. Weaver JC, Aizenberg J, Fanter GE, Kisailus D, Woesz A, Allen P, Fields K, Porter MJ, Zok FW, Hansma PK, Fratzl P, Morse DE (2007) Hierarchical Assembly of the Siliceous Skeletal Lattice of the Hexactinellid Sponge Euplectella aspergillum. J Struct Biol 158(1):93–106

    Article  PubMed  CAS  Google Scholar 

  12. Lichtenegger H, Reiterer A, Stanzel-Tschegg SE, Fratzl P (1999) Variation of cellulose microfibril angles in softwoods and hardwoods-a possible strategy of mechanical optimization. J Strut Biol 128(3):257–269

    Article  CAS  Google Scholar 

  13. Reiterer A, Burgert I, Sinn G, Stanzel-Tschegg S (2002) The radial reinforcement of the wood structure and its implication on mechanical and fracture mechanical properties—a comparison between two tree species. J Mater Sci. doi:10.1023/A:1014339612423

    Google Scholar 

  14. Speck T, Burgert I (2011) Plant stems: functional design and mechanics. Annu Rev Mate Res 41:169–193

    Article  CAS  ADS  Google Scholar 

  15. Seidel R, Bührig-Polaczek A, Fleck C and Speck T (2009) Impact resistance of hierarchically structured fruit walls and nut shells in view of biomimetic applications. In Proceedings of the 6th Plant Biomechanics Conference. French Guyana, France 2009. pp 406–411

  16. Seidel R, Thielen M, Schmitt C, Bührig-Polaczek A, Fleck C, Speck T (2010) Fruit walls and nut shells as an inspiration for the design of bio-inspired impact resistant hierarchically structured materials. In: Brebbia CA (ed) Design and Nature V. WIT Press, Southampton, pp 421–430

    Chapter  Google Scholar 

  17. Thielen M, Schmitt CNZ, Eckert S, Speck T, Seidel R (2013) Structure-function relationship of the foam-like pomelo peel (Citrus maxima)—an inspiration for the development of biomimetic damping materials with high energy dissipation. Bioinspir Biomim 8(2):1–10

    Google Scholar 

  18. Thielen M, Speck T, Seidel R (2013) Viscoelasticity and compaction behaviour of the foam-like pomelo (Citrus maxima) peel. J Mater Sci. doi:10.1007/s10853-013-7137-8

    Google Scholar 

  19. Fischer SF, Bührig-Polaczek A (2012) Evaluation and modification of the block mould casting process enabling the flexible production of small batches of complex castings. In: Srinivasan R (ed) Science and technology of casting processes. InTech, Rijeka, pp 88–114

    Google Scholar 

  20. Fischer SF, Thielen M, Loprang RR, Seidel R, Fleck C, Speck T, Bührig-Polaczek A (2010) Pummelos as concept generators for biomimetically inspired low weight structures with excellent damping properties. Adv Eng Mat 12(12):658–663

    Article  Google Scholar 

  21. Neinhuis C, Edelmann HG (1996) Methanol as a rapid fixative for the investigation of plant surfaces by SEM. J Microsc 184(1):14–16

    Article  Google Scholar 

  22. Vendra LJ, Brown JA, Rabiei A (2011) Effect of processing parameters on the microstructure and mechanical properties of Al–steel composite foam. J Mater Sci. doi:10.1007/s10853-011-5356-4

    Google Scholar 

  23. Kumar S, Kumar P, Shan HS (2008) Optimization of tensile properties of evaporative pattern casting process through Taguchi’s method. J Mater Process Tech 204(1–3):59–69

    Article  CAS  Google Scholar 

  24. Brevick JR, Davis JW, Dincher C (1991) Towards improving the properties of plaster moulds and castings. Proc Inst Mech Eng 205(4):265–269

    Article  Google Scholar 

  25. Borreguero AM, Carmona M, Sanchez ML, Valverde JL, Rodriguez JF (2010) Improvement of the thermal behaviour of gypsum blocks by the incorporation of microcapsules containing PCMS obtained by suspension polymerization with an optimal core/coating mass ratio. Appl Therm Eng 30(10):1164–1169

    Article  CAS  Google Scholar 

  26. Kim S, Kim M, Hong T, Kim H, Kim Y (2000) Investment casting of AZ91HP magnesium alloy. Met Mater Int 6(3):275–279

    Article  CAS  Google Scholar 

  27. Grugel RN (1993) Secondary and tertiary dendrite arm spacing relationships in directionally solidified Al–Si alloys. J Mater Sci. doi:10.1007/BF01151244

    Google Scholar 

  28. Kurz W, Fisher DJ (1989) Fundamentals of solidification. Trans Tech SA, Switzerland

    Google Scholar 

Download references


The authors would like to thank the RWP GmbH for their support during the simulation of the production process. Special thanks are extended to Dirk Freudenberg and his team for the realisation of the matrices, Jürgen Nominikat and Timm Ziehm for their support during the whole production process, Elke Schaberger-Zimmermann and Elke Breuer for the preparation of the metallographic sections, Michael Mathes for the SEM analyses and Franz Ernst for testing the tensile specimens. In addition to this, the authors gratefully acknowledge the financial support from the German Research Foundation (DFG) within the Priority Programme 1420.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Sebastian F. Fischer.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Fischer, S.F., Thielen, M., Weiß, P. et al. Production and properties of a precision-cast bio-inspired composite. J Mater Sci 49, 43–51 (2014).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: