Bi_2O_3-BaO-SiO_2-R_xO_y玻璃封接性能

Properties of Bi_2O_3-BaO-SiO_2-R_xO_y Glass for Sealing

系统研究Bi2O3-BaO-SiO2-RxOy(简写为Bi-Ba-Si-O)玻璃体系的封接性能。结果表明,该玻璃具有良好的热膨胀性能,热膨胀系数(CTE)为11×10-6K-1(50~530℃),与氧化钇稳定氧化锆(YSZ)(CTE:10.2×10-6K-1)电解质和SUS430(CTE:11.3×10-6K-1)合金连接体相匹配;实验确定该玻璃体系适宜的使用温度为(720±50)℃,并在720℃表现出良好的稳定性。用Bi-Ba-Si-O玻璃将YSZ电解质和SUS430合金连接体粘结后,三相界面结合紧密;三相界面处的元素分布分析结果表明,玻璃组分Si、Ba、Bi元素分别向电解质侧和合金侧有迁移;而合金内的Fe、Cr元素相对稳定,迁移较少。界面元素迁移有助于实现不同材料之间的连接,但需要关注其对长期性能的影响。实验选定的Bi-Ba-Si-O玻璃材料基本满足SOFC对封接材料的要求。

Sealing properties of Bi2O3-BaO-SiO2-RxOy (Bi-Ba-Si-O) glass was studied. The coefficient of thermal expansion (CTE) of the Bi-Ba-Si-O glass is 11×10-6 K-1 (50~530 oC), which can be matched with 8YSZ electrolyte (CTE: 10.2×10-6 K-1) and SUS430 steel interconnect (CTE: 11.3×10-6 K-1). The suitable sealing temperature of Bi-Ba-Si-O glass is (720±50) oC, during which the Bi-Ba-Si-O glass shows a very good thermal stability, especially at 720 oC. The SUS430 metallic interconnect and 8YSZ electrolyte could be well adhered by this glass. It is indicated that Si, Ba and Bi in the glass transmit to electrolyte and steel interconnect, whereas the Fe, Cr in the steel are more stable which show less transition. The transition of different elements to each other is helpful to form tightly adhere, as well as it may be related to the long term performance of components. As a conclusion, the Bi-Ba-Si-O glass could be used as sealing materials in SOFC.