Abstract
It has been tried to densify PbTiO3-PbZrO3-Pb(Zn, Nb)O3 piezoelectric ceramics by hot isostatic press(HIP)method.
Specimens were set in the chamber of HIP equipment without any sealed containers and sintered at atcmperature of 900-1200°C under a pressure of 170-1600 kg/cm2 in incrt gas atmospheres. Since the working gas was pure argon or nitrogen gas, the deoxidizing phenomenon was inevitable for some specimens in apart ofabatch. This phenomenon was easily observed by the change in color and the decrease ofelectrical resistivity. These deoxidized specimens were able to show the recovery by heat treatment at a temperatureof 800-1000°C in oxygen atmosphere. Isostatically hot pressed ceramics showed no defect on polished surface, the equivalent piezoelectric properties and a mechanical strength about 20% higher than that of thenormally sintered materials with a density of 97%.
