Microstructural study of Crofer 22 APU-glass interface for SOFC application

Glasses of composition (60−x)SiO2–15CaO–10Al2O3–(10 + x)Na2O–5TiO2 (x = 0, 5, 10, 15) were prepared. The crystallization kinetics of prepared glasses were investigated by differential thermal analyzer, dilatometer and X-ray diffraction techniques. In order to check the applicability of the prepared glasses as a sealant in solid oxide fuel cell, these were deposited on Crofer 22 APU steel by slurry technique and thermally treated. The interface of the glass–steel composites was further analyzed under scanning electron microscope in conjunction with energy-dispersive X-ray spectroscopy and X-ray dot mapping. All glass samples exhibit phase separation. The phase separation tendency increases with increasing content of Na2O in glasses. The N-10 glass containing 10% Na2O shows good adhesion with Crofer 22APU.