Microstructure, oxidation protection and failure mechanism of Yb2SiO5/LaMgAl11O19 coating deposited on C/SiC composites by atmospheric plasma spraying

► We designed a novel oxidation protective Yb2SiO5/LMA coating for C/SiC composites. ► Microstructure, oxidation protection and failure of the coating were investigated. ► The coating by APS bonds well with the substrate before and after thermal cycling. ► The coating significantly improves the oxidation resistance of substrate at 2273 K. ► The sintering of the coating and formation of bubbles make the coating fail.