Preparation of YSZ/Al2O3 micro-laminated coatings and their influence on the oxidation and spallation resistance of MCrAlY alloys

YSZ/Al2O3 micro-laminated coatings were successfully prepared on the surface of MCrAlY substrates by means of electrolytic deposition and microwave sintering. The as-prepared YSZ/Al2O3 coatings were characterized by high-resolution field emission SEM and XRD. Laminated structures of alternate YSZ and Al2O3 layers were observed in the coating with the phase composition of Y2O3 stabilized t-ZrO2, α-Al2O3 and θ-Al2O3. High-temperature cyclic oxidation test at 1000 °C in air was also performed to investigate the oxidation and spallation resistance of such coatings on MCrAlY substrates. The results indicate that such coatings exhibit not only excellent oxidation resistance but also good spallation resistance under thermal cycling due to the structure of multi-sealed Al2O3 layers and the preferable high-temperature mechanical properties induced by the designed laminated composite structures, respectively.