Highly oxidation resistant MCrAlY bond coats prepared by heat treatment under low oxygen content

Abstract

High-performance gas turbines and aircraft engines require high oxidation resistance MCrAlY bond coats. In this study, a novel heat treatment under low oxygen content was developed to prepare highly oxidation resistant MCrAlY bond coats. The results showed that after the heat treatment, metallic phases without as-deposited alumina film were exposed on the MCrAlY bond coat surface. The α-Al 2 O 3 thermally grown oxide (TGO) with a larger grain size was formed on the heat-treated bond coat surface during isothermal oxidation. This larger α-Al 2 O 3 TGO grain size significantly inhibited the TGO layer growth of MCrAlY bond coats by 2.7 times.