Superior high-temperature oxidation resistance of a novel (Al2O3–Y2O3)/Pt laminated coating

Abstract A 7-layer (Al 2 O 3 –Y 2 O 3 )/Pt laminated coating was successfully prepared on a Ni-based superalloy by magnetron sputtering methods. It is observed that the as-prepared coating has dense and refined brittle/ductile laminated nanostructure. Cyclic oxidation tests were adopted to investigate the oxidation and spallation resistance of this novel laminated coating. The results revealed that the 7-layer (Al 2 O 3 –Y 2 O 3 )/Pt laminated coating can significantly improve the high-temperature oxidation resistance and spallation resistance of the Ni-based superalloy. In such laminated coating, the multi-sealed (Al 2 O 3 –Y 2 O 3 ) and Pt layers can effectively suppress the inward diffusion of oxygen to an extremely low level, providing super oxidation resistance at 1200 °C for 1000 h. In addition, the excellent high-temperature mechanical properties of the (Al 2 O 3 –Y 2 O 3 )/Pt laminated coating are mainly induced by the increased thermal expansion coefficient and the brittle/ductile laminated composite structure by means of energy release mechanisms.