Herstellung und Prüfung festkörpergeschweißter Keramik-Metall-Verbindungen

Preparation and Testing of Solid-State Bonded Ceramic-to-Metal-Joints Ceramic-to-metal joints were manufactured by solid-state bonding in a R. F.-high-vacuum apparatus. The influence of welding temperature, welding time and welding pressure on the bond strength was investigated for an alumina/niobium-combination consisting of a layered composite ceramic-metal foil-ceramic. As a measure of bond quality the fracture resistance K_ICV was chosen. K_ICV date were obtained by the use of 4-point bend tests and tensile tests. For comparison, data are presented concerning the fracture resistance K_IC of the bulk alumina and the conventional bond strength of the joints. In addition to the Nb/Al₂O₃-data, K_ICV factors are determined for other metal/alumina combinations and for a Zr/Si₃N₄ joint. The present solid-state bonding apparatus was used for the preparation of the specimens. A device for high-temperature bend testing in a high vacuum was constructed. Some data for the high-temperature bond strength of solid-state bonded joints are given.