Enhanced interfacial bonding and superior oxidation resistance of CoCrAlY-TiB2 composite coating fabricated by air plasma spraying

In order to enhance oxidation resistance of titanium matrix materials, CoCrAlY-TiB2 coating is introduced by air plasma spray. Tensile test demonstrates that TiB2 addition promoted interfacial bonding strength with a maximum enhancing effect of 22.6%, which alleviated mechanical spallation of the coating and consequently gave rise to the improved physicochemical stability. Cyclic oxidation tests at 700, 800, and 900 degrees C reveal that weight gain of coated specimens reduced by 66.7%, 73.1%, and 75.2% compared with the TMCs substrate. The significantly enhanced anti-oxidation performance was mostly ascribed to the improved microstructural stability and the formation of dense Al2O3 and Cr2O3 oxides.