Rheological behaviors of suspension for zirconia-toughened alumina ceramics

The influences of mass fraction of adding dispersant, solid volume fraction, composition of powder and milling time on the rheological properties of zirconia-toughened alumina (ZTA) ceramic suspension were investigated by experiments of zeta potential and rheological behaviors etc. It is found that in the shear rate of 0-200 s^-1 all the rheological curves obtained under different conditions can be fitted with Casson model and Casson yield stress τ_c reflects well the stability of suspension. The results show that a relatively low τ_c for ZTA (20% ZrO₂, in mass, the same below) suspension can be obtained when the pH value is about 9.0 and mass fraction of adding dispersant is 0.90%. τ_c of suspension increases with the increase of solid volume fraction and content of ZrO₂. ZTA suspension with good stability can be prepared through adjusting content of adding dispersant when content of ZrO₂ is high. The suspension exhibits the lowest τ_c when the milling time is 4 h in the experiments.