Improved compressive strength of reticulated porous zirconia using carbon coated polymeric sponge as novel template

Strong reticulated porous zirconia was fabricated using a carbon coated polymeric sponge as a novel template. In this technique, a polymeric sponge was first coated with a carbon black slurry, before coating it with the zirconia slurry. The introduction of the additional fugitive carbon coating layer was used to make the severely curved triangular polymeric struts more round, consequently producing large rounded triangular voids within the sintered zirconia struts. The fabricated sample showed a high compressive strength of 0.85 ± 0.13 MPa at 96% porosity, which was much higher than that of the sample fabricated without the carbon coating layer (0.47 ± 0.11 MPa). This enhancement was attributed not only to the elimination of the crack-like defects at the apices of the triangular voids, but also to the increased resistance against the strut bending caused by the larger voids within the zirconia struts.