Fabrication and CaO–MgO–Al₂O₃–SiO₂ Corrosion Resistance of Multi-Component BaO–SrO–CaO–MgO–Al₂O₃–2SiO₂ Environmental Barrier Coatings

The multi-component ceramics of BaO–SrO–CaO–MgO–Al₂O₃–2SiO₂(BSCMAS) with different molar ratio of Ba,Sr,Ca,Mg were prepared by a conventional solid-state reaction. The fabrication procedure, CMAS corrosion resistance, and microstructures of BSCMAS were investigated. The results show that the multi-component ceramics of Ba_0.3Sr_0.3Ca_0.35Mg_0.05Al₂Si₂O₈(B_0.3S_0.3C_0.35M_0.05AS) can form a single-phase solid solution by adjusting the concentration of MgO. The CMAS corrosion of B_0.3S_0.3C_0.35M_0.05AS were carried out at 1250, 1300 ℃ and 1350 ℃. The B_0.3S_0.3C_0.35M_0.05AS showed better CMAS corrosion resistance than Ba_0.5Sr_0.5Al₂Si₂O₈. The sluggish diffusion of multi-component cations in B_0.3S_0.3C_0.35M_0.05AS leads to suppressing the interdiffusion of Ba—Sr with Ca—Mg, combined with the quick formation of anorthite to block the out-diffusion of Ba and Sr, resulting in the improved CMAS corrosion resistance of B_0.3S_0.3C_0.35M_0.05AS material.