Sound Absorption Properties of Al Foam
Aluminum foam with 0.2 g/cm3 density showed a good sound absorption property at frequencies higher than 2000 Hz. Compressed aluminum foam with an air gap of 50 mm or higher exhibited a very high sound absorption property near 400 Hz.
Hyung Sun Kim, Sang-Yeop Park, Bo Young Hur and Soo Wohn Lee
S. Y. Kim et al., "Sound Absorption Properties of Al Foam", Materials Science Forum, Vols. 486-487, pp. 468-471, 2005