Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-28T04:40:20.187Z Has data issue: false hasContentIssue false
  • English
  • Français

Compression Testing and Microstructure of Heat-Treatable Aluminum Periodic Cellular Metal

Published online by Cambridge University Press:  01 February 2011

B. A. Bouwhuis  and
G. D. Hibbard
B. A. Bouwhuis
Affiliation:
[email protected], University of Toronto, Materials Science and Engineering, 184 College Street, Toronto, Ontario, M5S3E4, Canada
G. D. Hibbard
Affiliation:
[email protected], University of Toronto, Materials Science and Engineering, 184 College Street, Toronto, Ontario, M5S3E4, Canada
Get access

Abstract

Periodic cellular metals (PCMs) can offer higher specific strengths and stiffnesses than conventional (i.e. stochastic) metallic foams. This study examines the effects of PCM microstructure and loading conditions on the mechanical performance.

PCM cores with 95% open porosity were constructed from perforated 6061 aluminium alloy sheets using a perforation-stretching method. This method places planar, periodically-perforated sheet metal in an alternating-pin jig. The pins apply force out-of-plane, plastically deforming the sheet metal into a truss-like array of struts (i.e. metal supports) and nodal peaks (i.e. strut intersections). Micro-hardness profiles were taken in the PCM struts to investigate microstructural evolution during fabrication and after heat treatment.

Truss cores were tested in two limiting uniaxial compression conditions. In the first, the PCM cores are placed between smooth compression platens where the nodes are laterally free and compressive forces are resisted through PCM node-bending (i.e. free compression). In the second, the PCM cores were placed between plates where the nodes are laterally confined and compressive forces are resisted through PCM beam-buckling (i.e. confined compression). Compression response was analyzed in terms of peak compressive strength, elastic modulus, and energy density absorbed upon densification; response values were used to illustrate the effect of compression test conditions. In addition, PCM cores were tested in the age-hardened state and annealed state to determine microstructural effects on compressive response.

Analysis of PCM response in free- and confined-compression conditions indicates a greater force resistance in beam-buckling over node-bending resistance mechanisms. The compressive strength, elastic modulus, and energy density of heat-treatable AA6061 PCMs are be found to respond: 1) over a wide range of value, dependent on the microstructure; 2) over a wide range of value, dependent on the PCM compression conditions; and 3) equally, if not more repeatable and with higher compressive strength-to-weight ratio than conventional metal foams.

Keywords

cellular (material form)microstructureAl
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 929: Symposium II – Materials in Extreme Environments , 2006 , 0929-II06-05
Copyright
Copyright © Materials Research Society 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Ashby, M. F., Evans, A. G., Fleck, N. A., Gibson, L. J., Hutchinson, J. W. and Wadley, H. N. G., Metal Foams: A Design Guide (Butterworth-Heinemann, Boston, 2000) pp. 3–72.Google Scholar
2. Davies, J. M., Lightweight Sandwich Construction (Blackwell Science, Toronto, 2001) pp. 1.Google Scholar
3. Ashby, M. F. and Bréchet, Y. J. M., Acta Mater. 51, 5801 (2003).Google Scholar
4. Ashby, M. F., Phil. Mag. 85, 3235 (2005).Google Scholar
5. Sypeck, D. J., App. Compos. Mat. 12, 229 (2005).Google Scholar
6. Wadley, H. N. G., Phil. Trans. Roy. Soc. A 364, 31 (2006).Google Scholar
7. Wadley, H. N. G., Fleck, N. A. and Evans, A. G., Compos. Sci. Tech. 63, 2331 (2003).Google Scholar
8. Chiras, S., Mumm, D. R., Evans, A. G., Wicks, N., Hutchinson, J. W., Dharmasena, K., Wadley, H. N. G. and Fichter, S., Int. J. Sol. Struct. 39, 4093 (2002).Google Scholar
9. Kooistra, G. W., Deshpande, V. S. and Wadley, H. N. G., Acta Mater. 52, 4229 (2004).Google Scholar
10. Tian, J., Kim, T., Lu, T. J., Hodson, H. P., Queheillalt, D. T., Sypeck, D. J. and Wadley, H. N. G., Int. J. Heat Mass Trans. 47, 3171 (2004).Google Scholar
11. Elzey, D. M., Sofla, A. Y. N. and Wadley, H. N. G., Int. J. Sol. Struct. 42, 1943 (2005).Google Scholar
12. Sypeck, D. J. and Wadley, H. N. G., Adv. Eng. Mat. 4, 759 (2002).Google Scholar
13. Deshpande, V. S. and Fleck, N. A., Int. J. Sol. Struct. 38, 6275 (2001).Google Scholar
14. Davis, J. R., ASM Specialty Handbook: Aluminum and Aluminum Alloys (ASM International, 1993) pp. 485–492, 686.Google Scholar
15. ASTM Standard E 3-99, Standard Test Method for Preparation of Metallographic Specimens (American Society for Testing and Materials, 1999).Google Scholar
16. ASTM Standard E 384-99, Standard Test Method for Microindentation Hardness of Materials (American Society for Testing and Materials, 1999).Google Scholar
17. ASTM Standard C 365, Standard Test Method for Flatwise Compressive Properties of Sandwich Cores (American Society for Testing and Materials, 1999).Google Scholar
18. Simone, A. E. and Gibson, L. J., Acta Mater. 46, 3109 (1998).Google Scholar
19. Krizst, B., Foroughi, B., Faure, K. and Degischer, H. P., Mat. Sci. Tech. 16, 792 (2000).Google Scholar
20. Andrews, E. W., Gioux, G., Onck, P. and Gibson, L. J., Int. J. Mech. Sci. 43, 701 (2001).Google Scholar
21. Ramamurty, U. and Paul, A., Acta Mater. 52, 869 (2004).Google Scholar
22. Andrews, E. W., Sanders, W. and Gibson, L. J., Mat. Sci. Eng. A 270, 113 (1999).Google Scholar
23. Bouwhuis, B. A. and Hibbard, G. D., submitted to Met. Mat. Trans. A (2006).Google Scholar
24. Olurin, O. B., Fleck, N. A. and Ashby, M. F., Mat. Sci. Eng. A 291, 136 (2000).Google Scholar
25. Salas, S., Hille, E. and Etgen, G. J., Calculus: One and Several Variables, 8th ed. (John Wiley & Sons, Inc., Toronto, 1999) pp. 264–266.Google Scholar