CHEN Hu, WU Yefan

(Jingdezhen Ceramic Institute, Jingdezhen，Jiangxi 333001)

Abstract: The effects of barium oxide, divalent metal oxide and silicon-boron ratio on BaO-Al₂O₃-SiO₂ sealing glass system were observed. BaO can make the structure of sealing glass looser and reduce its viscosity. With the BaO content increasing, thethermal expansion coefficient goes upward while the transition temperature Tg and the softening temperature Ts present anopposite trend. When the molar ratio of B₂O₃/SiO₂ is 0.35, 0.4, 0.5, and 0.6, the TEC of the sealing glass decreases with the B₂O₃/SiO₂ ratio increasing but the Tg and the Ts reduce significantly. But when the B₂O₃/SiO₂ ratio is greater than 0.5, it will have little effect on the Tg and the Ts, and the dropping trend of Tg and Ts gradually levels off. Introducing RO (R=Ca, Zn) into the system will raise the Tg to a higher temperature, and it will also increase the crystallization temperature of the sealing glass, which is not desirable for long stability of the sealing glass.

Key words: SOFC; borate; sealing