Gelation behavior and mechanical properties of gelcast lead zirconate titanate ceramics

Gelcasting is a novel forming method in fabricating complex ceramic parts. A low-toxicity gelling system with excellent properties based on Hydantion epoxy resin and 3,3′-Diaminodipropylamine (DPTA) was developed for gelcasting PZT ceramics. Effects of solid loading on the rheological properties, gelation behaviors and mechanical properties were investigated. The solid loading of PZT suspension which was suitable for the gelcasting reached as high as 55.0 vol%. The presence of PZT powder exhibited a catalytic effect of the polymerization reaction of the suspension calculated by the activation energy Ea. The mean flexural strength, the characteristic strength and Weibull modulus of the green bodies reached the maximum of 34.1 ± 3.3 MPa, 35.6 MPa and 11.1, respectively, when the solid loading was 55.0 vol%. After sintering at 1120 °C, excellent irregular shaped pillar accurately reproduced the form of the mold and the structural integrity maintained well over a large area.