Enhanced sound absorption performance of porous ceramics with closed-pore structure

To enhance the sound absorption performance of porous ceramics at low-to-medium frequencies, a novel porous ceramic with closed-pore structure was prepared through the addition of silicon carbide (SiC), which foamed at high temperature. The porous ceramic with closed-pore structure exhibited a better combination property than those without such pore structure. The results revealed a 69.6% improvement in the average sound absorption coefficient of porous ceramics with closed-pore structure compared to those without closed-pore structure at 200–1600 Hz. Furthermore, the sound insulation performance of porous ceramics with closed-pore structure exhibited a 150% improvement at 160–1600 Hz. Moreover, these ceramics featured a high open porosity from 65% to 82% when combined with sufficient compressive strength of 1.21–5.13 MPa and low thermal conduction of 0.126–0.198 W/m∙K, indicating a considerably promising combination of properties for noise control and reduction in corrosive environments at high temperature. These results indicated that the porous ceramic had sufficient strength, low thermal conduction, and good sound absorption performance, which was expected to be applied as the building insulation and acoustic damping material. Besides, this study provides a new method for enhancing the sound absorption performance of porous ceramics at low-to-medium frequencies.