Papers by Author: Stefan Baumann

Abstract: Tape casting is widely used in industrial scale for production of multilayer ceramic capacitors or substrates for different applications. In 2009, it was successfully introduced as standard shaping technology for 3 (BSCF) are shown. The entire scope from the preparation of the used powders, the different manufacturing steps and their optimization potential up to the final tape-cast product will be discussed. The influence of the use of pore forming agents, heat treatment or other parameters during processing will be described in detail. Finally, the option of sequential tape casting of different materials for graded structures as a future step in shaping technology will be presented for different applications.

Abstract: Ba_0.5Sr_0.5Co_0.8Fe_0.2O_{3 – δ} is a mixed ion-electron conductor with high application potential as high-temperature gas separation membrane. However, in practical use the integrity of this brittle perovskite is challenged by the mechanical boundary conditions of transient temperature exposure. Moreover, long term failure mechanisms such as static fatigue at room temperature and creep rupture at operation temperature might occur. The relevance of both effects for BSCF has been investigated. The slow crack growth at room temperature has been determined using bi-axial bending under different loading rates. The creep rupture at elevated temperature has been analyzed from three-point bending tests. The results indicate favourable behaviour of BSCF in both cases. A low risk of failure due to slow crack growth exists and the strain to failure in combined tensile - compressive mode reaches up to 40 %.