CHEN Hu WU Yefan

(Jingdezhen Ceramic Institute, Jingdezhen Jiangxi 333403, China)

Abstract:BaO-Al2O3-B2O3-SiO2 glass-ceramic sealing material suitable for solid fuel cells was prepared by traditional melting method. It belongs to multi-component glass. The XRD analysis of the samples heat-treated 100 h at 700 ℃, 800 ℃ and 900 ℃ shows that the main crystal phase is barium feldspar (BaAl2Si2O8) at 700 ℃; the barium feldspar from the precipitation is the main phase at 800 ℃; the reaction among raw materials is more complete and single-phase barium feldspar and a small amount of BaSiO3 crystals are produced at 900 ℃. When the content of Al2O3 is moderate (5 mol%), Al3+ exists in the glass system as a network modifier, which transforms [BO3] into [BO4] to improve the stability of glass; but with superfluous Al2O3, Al3+ acts as a network former, which transforms [BO3] into [BO4] to decrease the stability of glass. 

Key words:glass-ceramic; sealing material; borate glass