Additive manufacturing of architected ceramics foam for noise reduction

Abstract

Porous foams are routinely used for noise control applications; their open cellular structure provides good sound dissipation performance over a broad frequency range while retaining low bulk density. However, conventional acoustic foams cannot satisfy the mechanical and flammability constraints frequently encountered in aerospace applications. While fiberglass blankets are currently used for high temperature noise dissipation applications, their batch-to-batch performance variability and lack of mechanical stiffness remains an engineering hurdle. In this study, we investigate the viability of additively manufacturing ceramic foams for high temperature noise dissipation applications. We demonstrate the use of a low-cost, material extrusion 3D printer to fabricate ceramic foams with controlled porous architectures that can be tuned to provide exceptional sound absorption properties. The printed and sintered ceramic foams are tested using a normal incidence impedance tube and the effect of various print, sintering, and geometrical parameters on the acoustical impedance are studied. Our work shows that low-cost additive techniques present a viable step toward scalable fabrication of ceramic foams with tailored mechanical and acoustical properties.