Novel Al2O3–SiO2 aerogel/porous zirconia composite with ultra-low thermal conductivity

Abstract

Highly porous zirconia fibers networks with a quasi-layered microstructure were successfully fabricated using vacuum squeeze moulding. The effects of inorganic binder content on the microstructure, room-temperature thermal and mechanical properties of fibrous porous zirconia ceramics were systematically investigated. Al2O3–SiO2 aerogel was impregnated into fibrous porous ceramics, and the microstructures, thermal and mechanical properties of Al2O3–SiO2 aerogel/porous zirconia composites were also studied. Results show that the Al2O3–SiO2 aerogel/porous zirconia composites exhibited higher compressive strength (i.e., 1.22 MPa in the z direction) and lower thermal conductivity [i.e., 0.049 W/(m/K)]. This method provides an efficient way to prepare high-temperature thermal insulation materials.