coatings-sensitive-to-thermal-fatigueBlistering, ripplingdue to coatingbulges resulting fromcreep deformationunder cyclical stressCoating breaks out Spalling coatingSeparation frombase materialCoating cracksCrack in basematerialBase materialCoatingTypical damage symptoms of coatingsunder thermal fatigue loads:Coatings can be especially sensitive to thermal fatigueand influence the life span of parts considerably in thisway.Network of cracks in the diffusion coatingof a turbine stator vane segment. The cracks are expanded by hot gas corrosion.about 1 mmThermal fatigue damage in the coated inlet edgeof a cooled turbine blade. Noteworthy details include the enlargement of the cracks throughoxidation and the bulging of the coating.Oxidizedcooling air ductMetallographic cross-sectionCrumpling of a ductile coatingunder cyclical strain caused bycompressive stress resulting fromthermal strain differencesBallooning through oxidation below acracked diffusion coating