A novel glass-ceramic with high crystallinity for joining of SiC ceramic

Abstract A novel CaO-Al2O3-SiO2-Li2O (CASL) glass-ceramic filler with high crystallinity was used for joining SiC ceramic at 1260 °C for 10 min. The microstructure and interfacial structure of the joint were characterized in detail. The results showed that the anorthite and spodumene-wollastonite eutectic structure were the main products within the joint domain, and the glass-ceramic has a perfectly matched coefficient of thermal expansion with SiC. Besides, the glass-ceramic has a crystallinity of up to 95.9 wt% and remains thermal stability at 1000 °C. The characterization of the interface revealed the liquid glass can infiltrate into SiC grain boundary due to its good compatibility with SiC. The typical microstructure of joint was the SiC substrate/ CaAl2Si2O8 + LiAlSi2O6-CaSiO3 eutectic + glassy phase/the SiC substrate.