Abstract
The sintering process and the mechanism of reaction between PbO and PZT were investigated by using thermal dilatometer, chemical analysis, isothermal shrinkage and electron microscope.
Results obtained are summarized as follows.
(1) The sintering process was classified in the order of four stages; linear expansion (0-400°C), solid state reaction (400-750°C), shrinkage (750-850°C) and grain growth (800-900°C).
(2) The reaction rate was found to be expressed by the Dander's type and seemed to be controlled by diffusion.
(3) In the sintering of the specimen consisted of non-stoichiometric PZT associated with the liquid phase(PbO), the shrinkage was proportional to n power of the time, and the slope representing this relation was divided into three parts. These parts seemed to be due to rearrangement, solution-reprecipitation and grain growth of PZT. The slope of the solution-reprecipitation stage had the n value of about 1/3, which coincided with the case derived by Kingery, that is, the diffusion controlled mechanism of PZT in the presence of a liquid phase.
(4) This sintering specimen did not show an exaggerated grain growth within 180 minutes (firing time), at various temperatures.
