A comparative study on the microstructure evolution of conventional and nanostructured MCrAlY powders at high-temperature

Abstract Previous studies have revealed that nanostructured MCrAlY alloys with nano-oxide dispersoids show promising potential for high-temperature applications. In an effort to provide a fundamental understanding of microstructure-oxidation performance derived insights, the influence of nano-scaled microstructure and oxide dispersion on the oxidation behavior of MCrAlY powder material is investigated in this study. The microstructural evolution within the conventional and nanostructured powders was investigated during thermal exposure at 1000 °C for up to 100 h. The results indicated that a pure alumina layer was formed onto the surface of conventional powder and the thickness of Al2O3 layer increased gradually with the oxidation time. However, a duplex-structure comprising an outer spinel layer and an inner alumina layer was formed onto the surface of the nanostructured powder. The different oxidation mechanisms of the two powders were discussed.