Fabrication of ultrahigh porosity ceramics with biaxial pore channels

We fabricated highly porous ceramics having biaxial pore channels using a combination of CNC-machining and ceramic dip-coating methods. For this goal, the graphite template having one interconnected pore channel was prepared using the CNC-machining and lamination, and then dip-coated with tetragonal zirconia polycrystal (TZP) slurry, followed by heat-treatment at 900 °C for 3 h in air to remove the graphite template and at 1400 °C for 3 h to sinter TZP walls. This heat-treatment produced an addition 3-D channel as a representative of the graphite template, while preserving the preexisting channel, thereby allowing the sample to have biaxial pore channels. The fabricated sample showed ultra-high porosity (∼ 91%) and high compressive strength (∼ 6.5 MPa), as well as having a well controlled 375-μm² pore structure.