BEHAVIOR OF PBO IN THE 2-STAGE SINTERING OF PLZT CERAMICS

The role of excess PbO in liquid phase sintering of PLZT ceramics has been studied by a modified two-stage atmosphere sintering method. In the first stage of sintering the results showed that the densification rate of PLZT ceramics is strongly dependent on the amount of excess PbO, and a 13 vol.% liquid is enough to obtain a fully dense PLZT by the particle rearrangement process. The second sintering stage was adopted to remove the liquid phase PbO to achieve transparency. The kinetics of evaporation of PbO in the second stage were also examined. Experimental results verified the formula (Pb-1-(3x/2)La-x/2(ZryTi1-y)O-3 for the PLZT ceramics; and owing to high sinterability, their relative densities did not decrease through vaporization loss of PbO.