Abstract
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.
Highlights
Cellular materials constitute a new and attractive class of products with a wide variety of structural and functional applications
The sound absorption coefficients found for these aluminium foams were compared to the coefficient for commercial foams marketed under the name ALPORAS
The normal incidence absorption coefficient was measured in 5, 10, 20- and 40-mm thick samples of aluminium foams Espuma 1 (E1), Espuma 2 (E2), Espuma 3 (E3), Espuma 4 (E4) and the ALPORAS product
Summary
Cellular materials constitute a new and attractive class of products with a wide variety of structural and functional applications. Foremost among the methods used to produce metallic foams are those in which the structure is generated by adding a foaming agent to the molten metal or by foaming solid precursors that contain certain amounts of foaming agent (1-2). In addition to their low specific weight, metallic foams feature a series of mechanical, thermal and acoustic properties that make them well suited applications in the automotive, biomechanical and construction industries (1-3). While metallic foams have been made from titanium, copper, magnesium and steel for their high corrosion resistance and low melting points, the material that has been most widely studied in this context is aluminium and its alloys
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
