Investigation of the influencing factors on surface exfoliation on Al2O3–ZrO2 green bodies prepared by gelcasting

The composite Al2O3/ZrO2 ceramics was made by gelcasting in air and nitrogen ambience, respectively, at low temperature, with and without temperature gradient, respectively, to study the influencing factors on the surface exfoliation of green bodies. The surfaces of the ceramic green bodies formed under various conditions were characterized by SEM and FTIR techniques. The results showed that the temperature gradient and oxygen can inhibit the polymerization of AM/MBAM monomer and lead to surface exfoliation of the green bodies. And no polymerized monomer exhibited and the strength of green bodies was extremely low at low temperature, which can be solved by eliminating temperature gradient and removing O2 to solidify the ceramic slurry at a high temperature. We found that the well-developed binder networks of the polymerized monomers were formed not only in entrails but also in surface of the green bodies, confirmed by FTIR analysis and SEM.