Shaw-Bing Wen

Tape Casting and Crystallization Kinetics of Ce0.8Y0.2O1.9

An aqueous tape casting of Ce0.8Y0.2O1.9 (YDC) ceramics was developed using poly(acrylic acid) (PAA) as a dispersant, poly(vinyl alcohol) (PVA) as a binder, poly(ethylene glycol) (PEG) as a plasticizer, and deionized water as a solvent. The surface properties of YDC powder with and without PAA dispersant were characterized by zeta potential. The rheological of the YDC slurries was evaluated with a rotary viscometer. The zeta potential measurement showed that the isoelectric point for YDC powders in the absence of dispersant had a pH value of 3.35. The experiment results showed that the pH value greatly affects the rheology of the slurry. In the presence of 2 wt % PAA dispersant, 55 wt % YDC powders exhibited shear thinning behavior, indicating that YDC slurry was homogenous and well stabilized. With an appropriate formulate, homogeneous, smooth, and defect-free green tapes were successfully obtained. Moreover, the crystallization kinetics of YDC powders prepared by the coprecipitation process has also been investigated in this study. The activation energy of crystallization was calculated on the basis of differential scanning calorimetry (DSC) at different heating rates. The activation energy of crystallization presented a value of 192.8 kJ/mol.