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

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.