Ultra-high-porosity zirconia ceramics fabricated by novel room-temperature freeze-casting

Ultra-high-porosity zirconia ceramics with interconnected pores were prepared by freezing zirconia/camphene slurries with solid loading ranging from 10 to 20 vol.%, followed by freeze-drying in air and subsequent heat treatment at 1500 °C for 2 h. All of the fabricated samples showed highly porous microstructures with moderate pores ranging from 20 to 50 μm in size. The porosity varied between 82% and 67%, while the compressive strength was significantly improved from 41 to 63 MPa.