ISBN 9783843936163

978-3-8439-3616-3, Reihe Werkstoffwissenschaften

Zongwen Fu
Untersuchungen der Anisotropieentstehung beim Foliengießen

141 Seiten, Dissertation Universität Erlangen-Nürnberg (2018), Softcover, A5

Zusammenfassung / Abstract

The main purpose of this study was to investigate the origin of anisotropic effect in tape cast products. For this aim, dynamic fluid mechanics during the casting process were experimentally, mathematically and numerically investigated. Furthermore, the drying behaviors of ceramic tapes, such as drying speed, drying shrinkage and drying stress, were characterized by using cantilever deflection and interference method under different process parameters. In dried green tapes the inhomogeneous binder and porosity distribution, which were induced by capillary forces and constrained drying effect, were analyzed along the thickness direction. During binder burnout process it was found, that the shrinkage anisotropy of ceramic tapes already occurred at low temperatures; i.e. the debinding shrinkage had significant influence on the anisotropic sintering shrinkage. By means of image analysis based on the modified linear intercept method, the microstructural anisotropy (e.g. particle and pore orientation) was correlated in all three spatial directions with the shrinkage anisotropy after sintering at different temperatures. With increasing particle shape anisotropy, the particles and pores in the microstructure of ceramic tapes were significantly aligned in the casting direction; simultaneously higher shrinkage anisotropy after sintering was observed. The use of spherical and platelet-shaped particles could lower or higher the microstructural and also the shrinkage anisotropy in the respective films.