Entwicklung von kristallisierenden Glasloten für planare Hochtemperatur-Brennstoffzellen

Glass and glass ceramic sealants are developed for high temperature planar SOFC meeting the requirements of high thermal expansion (11.0 to 12.0×10-6 K-1), high electrical resistance > 2 kW/cm2, good thermochemical compatibility with the other fuel cell materials, and stability under H2 and H2O atmospheres at an operation temperature of 800 oC for over 40,000 h. Experimental results in terms of crystallization behavior, thermal expansion coefficient, crystalline phase content, wetting and joining properties, microstructure, interfacial reaction mechanisms, as well as the long term stability of the thermal expansion coefficient, mineral phases, sticking, and stability against reactive evaporation were discussed. Compositions of glasses were developed by a theoretical approach termed constitutional compound calculation. Glasses from the system BaO-CaO-Al2O3-SiO2 (B-C-A-S) display high thermal expansion, higher than glasses from the system MgO-CaO-Al2O3-SiO2. After performing a systematic investigation to the entire BaO-CaO-Al2O3-SiO2 system, the properties of suitable glass were optimized by additional oxides. Finally, a specific formula termed S25 was found to be the optimum sealant. Long term stability tests showed good sticking, low evaporation loss, and good gas tightness. Observations by heating microscope, DTA, and investigation of the interfacial microstructure lead to a conclusion that good sticking requires a low viscosity, low surface tension and slow crystallization. Interlocking between glass sealant and steel was achieved under joining conditions in a strong reducing atmosphere.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2003

Author dc:creator

• Geasee, Pisit

Contributors dc:contributor

• Conradt, Reinhard

• info:eu-repo/classification/ddc/620
• Glaslot
• Produktentwicklung
• Hochtemperaturbrennstoffzelle
• Lötverbindung
• Ingenieurwissenschaften
• Fügen mit Glas
• Glaseigenschaften
• Brennstoffzelle
• Glaslotentwicklung
• Werkstofftechnik

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123561%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:61955