Influence of Al2O3 addition on the properties of Bi2O3–BaO–SiO2–RxOy (R = K, Zn, etc.) glass sealant

Abstract A series of Bi 2 O 3 –BaO–SiO 2 –R x O y (designated BiBaSi glass) glass sealants doped with different contents of α-Al 2 O 3 have been investigated. Al 2 O 3 was added as a modifier to affect the structure and the behavior of the glass. The thermal properties such as glass transition temperature (Tg), softening temperature (Tf) and coefficient of thermal expansion (CTE) were measured by a dilatometer. The sealing performance was investigated by sealing a SOFC single cell stack and measuring its open circuit voltage (OCV). Tg, Tf and suitable usage temperature of the sealants increased with increasing Al 2 O 3 content in the glass, while CTE decreased. When the Al 2 O 3 content was lower than 10 wt.%, excellent sealing performance was observed.