Sound absorption properties of ceramic hollow sphere structures with micro-sized open cell

Abstract Porous structure with micro-sized open cell was tailored for the sound absorption, and ceramic hollow sphere structures (CHSS) were prepared by low temperature pre-bonding and curing process. Micro-sized open cells of CHSS, which demonstrated normal/bimodal distribution, were mainly observed in the interstitial gaps of fly ashes. The CHSS with micro-sized open cells demonstrated a broadband sound absorption above 500 Hz, and its acoustics behavior was affected significantly by the porous structure. The calculated values of sound absorption based on the Pride–Allard model demonstrated similar trends as experimental results with the increase of frequency.