Life Prediction of High-Temperature MCr AIY Coatings Based on Microstructural Observations

• Thermal barrier coatings are commonly used in gas turbines for protection against high tem-perature and oxidation. Life prediction of oxidation protective coatingsmay be done bymicrostructure-based techniques such as -depletion based life criteria. In this study, a thermal barrier coating sys-tem, with an overlay NiCoCrAlY coating as bond coat, was oxidised up to 10000 h at 900 C. Themicrostructure was studied and related to Al depletion. It was found that a -depletion based lifecriterion could not be used for the studied coating composition and temperature as it would be tooconservative. A 0-depletion based model was instead suggested and supported by interdiffusion sim-ulation.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

Keyword

MCrAIY

TBC

thermal barrier coating

life prediction

microstructure

Al depletion

Publication and Content Type

ref (subject category)

kon (subject category)