Acoustic performance of metallic foams

Metallic foams are among the most promising class of materials due to their unique mechanical properties combining low mass with high stiffness, excellent energy absorption, and vibroacoustic damping. Consequently, noise control using methodically engineered metallic foams has received increased attention from both industrial and scientific community. Accordingly, this paper aims to present the mechanism of sound absorption along with the experimental and theoretical procedure that can be used to classify metallic foams. Additionally, the influence of design parameters on the resulting sound absorption coefficient of closed and open-cell metallic foams are explored. While Aluminium foams used to dominate the literature when it comes to acoustics, recent studies have reported Nickel-Inconel superalloy and Copper foams as having superior sound absorption coefficients.