A Comparison Of The Activation Energy Determination For Crystallization By Differential Thermal Analysis And Shrinkage By Hot Stage Microscopy For Lead-Zincborosilicate Glass Ceramics During Sintering

Abstract

Particular sintering behavior may be found for some kind of ceramic materials where shrinkage is stopped before reaching the shrinkage outset. Crystallization of glass powder can stop shrinkage during sintering. Thermal characterization of the crystallization process is developed by applying the modified Ozawa and Kissinger models. Herein, we propose to use the same models to study the shrinkage patterns that can be observed during sintering obtained by Hot Stage Microscopy. Then, a question may arise: Is it possible to establish a connection between crystallization and shrinkage? We test the hypothesis that the shrinkage stop activation energy should be closed to one of the crystallization activation process. It is obtained that shrinkage stop activation energy is higher that crystallization activation energy by 40 – 50 kJ/mol. This is an expected result because the effect of crystallization on the stop of shrinkage is retarded and can be observed at a higher temperature.