A self-healing environmental barrier coating: TiSi₂-doped Y₂Si₂O₇/barium strontium aluminosilicate coating

The TiSi₂-doped Y₂Si₂O₇/barium strontium aluminosilicate (BSAS) coating was fabricated on C/SiCs and corroded in a 50%H₂O–50%O₂ environment at 1250 °C. The C/SiCs coated with TiSi₂-doped Y₂Si₂O₇/BSAS showed better durability than that coated with Y₂Si₂O₇/BSAS. Microstructural studies showed that the through-thickness cracks in the TiSi₂-doped Y₂Si₂O₇/BSAS coating were filled with the oxidation products of TiSi₂, indicating that the TiSi₂-doped Y₂Si₂O₇/BSAS coating has self-healing properties. Furthermore, the Y₂Si₂O₇/BSAS coating doped with 15 wt% TiSi₂ showed better durability than those doped with 10 wt% and 20 wt% TiSi₂, indicating that 15 wt% TiSi₂ is the optimum doping amount for Y₂Si₂O₇/BSAS coatings.