Acoustic properties of aluminium foams
DOI:
https://doi.org/10.3989/mc.2008.v58.i291.109Keywords:
sound absorbers, absorption coefficient, impedance tubeAbstract
The article discusses normal incidence sound absorption by aluminium foam manufactured with powder metallurgy technology. Aluminium foams with different surface morphologies were obtained by varying the type of precursor and adding filler materials during the foaming process. The sound absorption coefficients found for these aluminium foams were compared to the coefficient for commercial foams marketed under the name ALPORAS. The effect of foam thickness on the absorption coefficient was studied for each sample prepared.
The combination of good acoustic and mechanical properties makes aluminium foams particularly attractive products. The study included an analysis of the effect of 2-, 5- and 10-cm air gaps on the sound absorption coefficient. The results showed that such gaps, which are routinely used in construction to reduce the reverberation period in indoor premises, raised the low frequency absorption coefficient significantly. This increase was found to depend on aluminium foam density and thickness and the depth of the air gap. In this same line, we have investigated the absorption coefficient of the aluminium foams combined with a mineral fiber panel.
Downloads
References
(1) Banhart J.: “Manufacture, characterisation and application of cellular metals and metal foams”, Progress in Materials Science, vol. 46 (2001), pp. 559-632. doi:10.1016/S0079-6425(00)00002-5
(2) Baumeister J., Banhart J. and Weber M.: “Aluminium foams for transport industry”, Materials and Design, vol. 18 (1997), pp. 217-220. doi:10.1016/S0261-3069(97)00050-2
(3) Banhart J. and Weaire D.: “On the road again: metal foams find favour”, Physics Today, (2002), pp. 37-42. doi:10.1063/1.1506749
(4) Lu T. J.: Hess A. and Ashby M. F.: “Sound absorption in metallic foams”, Journal of Applied Physics, vol. 85 (1999), pp. 7528-7539. doi:10.1063/1.370550
(5) Allard J. F., Propagation of sound in porous media, Elsevier Science Publishers, Inglaterra 1993.
(6) Umnova O., Attenborough K., Sin H. and Cummings A.: “Deduction of tortuosity and porosity from acoustic reflection and transmission measurements on thick samples of rigid-porous materials”, Applied Acoustics, vol.66,(2006),pp.607-624. doi:10.1016/j.apacoust.2004.02.005
(7) García Cambronero L. E., Pozas A., Ruiz Román J. M. and Suarez J. C.: “Efecto del tamaño de partícula del TiH2 en el comportamiento a compresión de espumas de AA6061+10SiC”, XI Congreso Nacional de Materiales, 20-23 de Junio (Vigo, 2006), pp. 847-850.
(8) García Cambronero L. E., Ruiz Román J. M., Cañadas I. and Martínez D.: “Características de la estructura celular en espumas de Al-7Si con mármol obtenidas mediante energía solar concentrada”, XI Congreso Nacional de Materiales, 20-23 de Junio (Vigo, 2006), pp.
(9) Baumeister, J.: US Patent 5151246, 1992.
(10) Seybert A. F. and Ross D. F., “Experimental determination of acoustic properties using a two-microphone randomexcitation technique”, Journal of Acoustics of American Society, vol. 68 (1980), pp. 1362-1369.
(11) ISO 10534-2: 1998, Acoustics determination of sound absorption coefficient and impedance or admittance by the impedance tube. Part II: Transfer function method.
(12) Bodén H. and Abom M.: “Influence of errors on the two-microphone method for measuring acoustics properties in ducts”, Journal of Acoustics of American Society, vol. 79 (1986).
(13) Seybert A. F. and Soenarko B.: “Error analysis of spectral estimates with application to the measurement of acoustic parameters using random sound fields in ducts”, Journal of Acoustics of American Society, vol. 69 (1981), pp. 1190-1199. doi:10.1121/1.385700
(14) Gibson L. J. and Ashby M.: Cellular Solids: structure and properties, 2º edition, Solid State Science, Cambridge University Press, UK (1997).
(15) Liu Z. and Scanlon M. G., “Scaling Young’s modulus of cellular solids”, Journal of Materials Science Letters, vol. 22 (2003), pp. 547-548. doi:10.1023/A:1022950706432
(16) Tuner E. and Wegener W., “Elastic properties of highly anisotropic thin poly(propylene) foam”, submitted to Elseiver Science.
(17) Sgard F. C., Olny X., Atalla N. and Castel F.: “On the use of perforations to improve the sound absorption of porous maerials”, Applied Acoustics, vol. 66 (2005), pp. 625-651. doi:10.1016/j.apacoust.2004.09.008
(18) Kinsler L. E., Fret A. R., Coppens A. B. and Sanders J. V., “Fundamentos de acústica”, Ed. Limusa, 1995.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2008 Consejo Superior de Investigaciones Científicas (CSIC)
This work is licensed under a Creative Commons Attribution 4.0 International License.
© CSIC. Manuscripts published in both the print and online versions of this journal are the property of the Consejo Superior de Investigaciones Científicas, and quoting this source is a requirement for any partial or full reproduction.
All contents of this electronic edition, except where otherwise noted, are distributed under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence. You may read the basic information and the legal text of the licence. The indication of the CC BY 4.0 licence must be expressly stated in this way when necessary.
Self-archiving in repositories, personal webpages or similar, of any version other than the final version of the work produced by the publisher, is not allowed.
