Enhanced thermal shock resistance of SiC_f/SiC composites with Y-Al-Si-O glass ceramic environmental barrier coatings in water-oxygen conditions at 1350°C

In this study, Y-Al-Si-O(YAS) glass-ceramic environmental barrier coatings were prepared after modifying CVI-SiC_f/SiC composites with microcrystalline glass. The resistance of both SiCf/SiC and SiC_f/SiC with YAS-EBC to thermal shock was systematically examined using a water quenching method. The findings demonstrate that the SiC_f/SiC composites with YAS-EBC exhibits outstanding thermal shock resistance. The coefficient of thermal expansion (CTE) of the YAS coating exhibits minimal deviation from that of SiC_f/SiC and possesses a low modulus of elasticity. Upon experiencing thermal shock, the YAS coating is subjected to tensile stress, with an average thermal stress of merely ∼4.4 MPa. After undergoing 100 cycles, there was no evidence of debonding between the coating and the substrate, nor was a thermally grown oxide (TGO) layer observed at the interface. This research provides a credible method and theoretical foundation for enhancing the thermal shock resistance behavior of CVI-SiC_f/SiC composites.