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.

Environmental barrier coating (EBC) materials that are resistant against molten calcia-magnesia-aluminosilicate (CMAS) corrosion are urgently required. Herein, multicomponent rare-earth (RE) disilicate ((Yb_0.2Y_0.2Lu_0.2Sc_0.2Gd_0.2)₂Si₂O₇, (5RE)₂Si₂O₇) was investigated with regard to its CMAS interaction behavior at 1400 ℃. Compared with the individual RE disilicates, the (5RE)₂Si₂O₇ material exhibited improved resistance against CMAS attack. The dominant process involved in the interaction of (5RE)₂Si₂O₇ with CMAS was reaction-recrystallization. A dense and continuous reaction layer protected the substrate from rapid corrosion at high temperatures. The results demonstrated that multicomponent strategy of RE species in disilicate can provide a new perspective in the development of promising EBC materials with improved corrosion resistance.

Carbon fiber reinforced silicon carbide-hafnium carbide (C/SiC-HfC) composite was prepared by precursor infiltration and pyrolysis process. Then, ablation behavior of C/SiC-HfC was evaluated in plasma wind tunnel. It was found that oxide layer formed during ablation significantly influenced the surface temperature. Formation of dense HfO₂-SiO₂ layer under low heat flux led to stable surface temperature. Silica (SiO₂) on the surface was gradually consumed when heat flux increased, resulting in conversion of HfO₂-SiO₂ on the surface to HfO₂. Converted HfO₂ with high catalytic coefficient absorbed more energy, causing gradual increase in the surface temperature. Formed oxide layer was destroyed at high heat flux and high stagnation point pressure. After carbon fiber lost the protection of HfO₂-SiO₂ layer, it burned immediately, leading to surface temperature jump.