DU Zhenbo 1,3, FAN Shangqing 1,3, HE Xuan 1, ZENG Renjie 1,2
(1. College of Materials, Xiamen University, Xiamen, Fujian 361005; 2. Fujian Provincial Key Laboratory of Advanced Materials, Xiamen, Fujian 361005; 3. Parkathings Amorphous Materials Technology Co., Ltd., Xiamen, Fujian 361101)
Abstract: ZnO -Bi2O3 -B2O3 glasses with Y2O3 addition for SOFC sealing were investigated. Structure and glass transition temperature (Tg) of the glasses prepared by “melting-quench” were studied by Infrared spectroscopy, Raman spectroscopy and differential thermal analyzer; crystallization, thermal expansion coefficient (α) and volume resistivity (ρ) of the glasses prepared by “molding-heat treatment”were studied by X-ray diffraction, dilatometer and high resistance meter. The results show: α decreases significantly with the addition of Y2O3 ≤ 0.5~1.0wt.% to glasses for Y2O3 promotes [BO3] to [BO4] which strengthens the network; while Y2O3 ≥ 0.5~1.0wt%, α declines not so significantly for the increase of Bi-O content in the glasses; the effects of Y2O3 addition on the glasses may change from weakening the network to strengthening the network with the content of Y2O3 increasing, which leads to Tg decrease at first and then increase; Y2O3 addition on glasses can inhibit crystallization; crystallization can improve α and ρ. Though adding Y2O3 to the glasses causes α and ρ to decline, the value of α and ρ are still within the sealing requirements of SOFC.
Key words: melting temperature; softening temperature; rare earth; solid oxides fuel cell