Rheological properties of BaZr_0.1Ce_0.7Y_0.1Yb_0.1O_3−δ (BZCYYb1711) tape casting slurry and analysis of aggregation behavior

Rheological properties of BaZr_0.1Ce_0.7Y_0.1Yb_0.1O_3−δ (BZCYYb1711) tape casting slurry is studied for the uniform, dense BZCYYb1711 tapes. The rheological characteristics of the slurry are analyzed with respect to sequential segments: powder + solvent (Seg.1), Seg.1 + dispersant (Seg.2), Seg.2 + plasticizer (Seg.3), and Seg.3 + binder (Seg.4). The aggregate structure under shear rate (D = 10–200 s⁻¹) at different BZCYYb1711 powder volume fractions ( \(\phi = 0.05 - 0.30\) $\varphi =0.05-0.30$ ) is investigated. It was confirmed that there are differences in the gel point in each segment, implying chemical additives influence the binding mechanism between particles. Based on these results, the fractal dimension (d_f) and shear dependence (m) were determined, confirming the formation of hard aggregates. Utilizing equations related to aggregate properties, the behavior of aggregates in each segment was analyzed. Additionally, viscosity behavior prediction models were employed to deduce the bonding strength within aggregates. Finally, the slurry composition was tested by tape casting and comparing the microstructure, mechanical property of green tapes made from the selected slurries.