Optimisation of sintering processes for porcelain using in-situ measuring methods

Abstract

By monitoring the thermal conductivity of ceramic materials during sintering, direct insight into the microstructural evolution can be gained. Using an in-situ thermooptical measuring system for measurement of thermal conductivities and densification rates and a high-temperature X-ray diffractometer, sintering mechanisms of porcelain have been examined. For the investigation of fast biscuit and glost firing cycles of whiteware, a firing process of a continuosly gas fired kiln with a firing atmosphere containing water vapourwas simulated in a resistance heated laboratory fumace. The sintering properties deviate significantly from results obtained in dry air. From densification data, a „kinetic field" for the glost firing of whiteware has been setup to calculate optimal fast firing cydes and to determine the activation energy for the densification. The activation energy increases in the intermediate sintering stage.