전자빔 증착법에 의한 열차폐코팅의 고온 내산화성 평가

Abstract

Failure mechanisms of electron beam physical vapor deposited thermal barrier coatings(EB-PVD TBCs) that occur during thermal cyclic oxidation were investigated. The investigations include microstructural degradation of NiCrAlY bond coat, thermally grown oxides(TGOs) along the ceramic top coat-substrate interface and fracture path within TBCs. The microstructural degradation of the bond coat during cyclic oxidation created Al depleted zones, resulting in reduction of NiAl and g-Ni solid solution phase. It was observed that the fracture took placed primarily within the TGOs or at the interfaces between TGOs and bond coat.