Current state of in situ measuring methods for the control of firing processes

Abstract

A combination of in situ measuring methods and computer simulation is suggested for the optimization of debinding and sintering processes in lab furnaces. From the optical measurement of sintering shrinkage and the mass loss measurement during debinding the respective reaction rates are derived. A high resolution of 1 μm and a reproducibility better than 0.3% were obtained for the optical measurement of sintering shrinkage. The atmospheres in the in situ measuring furnaces have to be closely matched to the production furnaces, to allow a transfer of the optimized heating cycles. A kinetic field method is used to obtain a model-free prediction of the debinding and sintering kinetics. Various other macroscopic in situ measuring methods are discussed, regarding their role during process optimization of ceramics. For example, heat transfer properties, required to calculate temperature and stress distributions during the heat treatment, were obtained by a modified laser-flash technique. © 2008 The American Ceramic Society.