Effect of particle morphology of Al₂O₃ on gelcasting of ZrO₂/Al₂O₃ ceramics

The rheological behaviors of the ZrO₂/Al₂O₃ (ZTA) suspension were investigated using three kinds of Al₂O₃ with different particle morphology. ZrO₂/Al₂O₃ green bodies and ceramics were prepared by using a low-toxicity monomer N, N-dimethyl acrylamide (DMAA) as gelling agent. The effect of dispersant dosage, milling time and solid loading on the rheological properties of suspension were discussed. Tabular Al₂O₃ powders have good effect on decreasing viscosity of slurries and clubbed Al₂O₃ powders are good for flexural strength of green bodies. The particles in ZrO₂/Al₂O₃ green bodies are combined closely and their bending strength can reach 21.45, 19.87, 25.90 MPa, respectively. Granular Al₂O₃ powders are beneficial properties of sintered ceramics, and the mean bending strength and fracture toughness of sintered ceramics are 680 MPa and 7.49 MPa·m^1/2, 453.1 MPa and 6.8 MPa·m^1/2, 549.4 MPa and 6.34 MPa·m^1/2.