Glass-to-metal seals for solid oxide cells at the Politecnico di Torino, an overview

A summary and update of the research on the design, process, and testing of glass and glass-ceramic to metal seals for solid oxide cells (SOC) conducted during the last 13 years at the Politecnico di Torino, Italy, within our research group and with several international collaborations, is presented and discussed. Glass and glass-ceramic-based materials play a key role in SOC performance and durability as well as in the sealing and joining of metallic interconnects. The sinter-crystallization method is a powerful technique that is used to obtain dense and reliable glass-ceramics capable of providing hermetic joining and seals. The issues, learned from our experience, that have an impact on the lifetime behavior of glass and glass-ceramic to metal seals are briefly reviewed in terms of challenges and working conditions. The mechanical characterization of glass-to-metal seal materials has a crucial impact on the overall performance, as the metal-glass interface plays a key role on the final joining strength and reliability. Several glass compositions are presented along with results on their characterization and behavior as joining materials for metallic interconnects, with a focus on their potential use as SOC seals.