Enhancing durability in high-temperature environments: Insights into B_xS_1-xAS-based environmental barrier coatings

Barium-strontium aluminosilicate (B_xS_1-xAS) environmental barrier coatings (EBCs) are pivotal in protecting continuous fiber-reinforced silicon carbide ceramic matrix composites (SiC-CMCs) from harsh gas environments, thereby extending their service life. However, the performance of B_xS_1-xAS degrades due to exposure to high-temperature wet oxygen, corrosive media, thermal shock, and foreign object impacts. This paper systematically investigates the failure mechanisms of B_xS_1-xAS-based EBCs under these conditions and explores strategies to enhance their durability. Key failure mechanisms include surface volatilization, phase-change-induced cracking, and accelerated degradation due to coupled factors such as high-velocity steam and corrosive media (like CMAS and Na₂SO₄). The study also highlights the role of thermal growth oxide (TGO) formation and its contribution to stress-induced coating delamination. To address these challenges, this paper reviews advanced strategies such as elemental doping, material composites, and/or structural design optimization. These approaches aim to improve the corrosion resistance, mechanical robustness, and overall service life of B_xS_1-xAS-based EBCs. Furthermore, the development of comprehensive evaluation systems and digital platforms is emphasized to accelerate material design and optimize coating performance. Advancements in surface treatment and repair technologies are identified as critical for enabling the engineering applications of these coatings.