Effect of rheological properties of the suspension on the mechanical strength of Al2O3–ZrO2 composites prepared by gelcasting

The bending strength and Weibull modulus of sintered ZTA parts prepared from Al2O3–ZrO2 (15 vol.%) suspension by the gelcasting process were investigated. The solid loading of the suspension that can meet the casting process requirements can reach 55%. However, it is found, surprisingly, that the highest bending strength and the largest Weibull modulus reached values as high as 791.58±33.42 MPa and 24.38 only when the solid loading of the suspension was 50 vol.%. The reason for this phenomenon is that the microstructure of the sintered samples is to a large extent determined by the structure and the rheological behavior of the suspension because the gelcasting process is an in situ curing process.