INFLUENCE OF CYCLIC STRAIN ON LIFE OF A PVD TBC

A thermal mechanical fatigue (TMF) test has been developed to determin e the effect of strain on the life of a thermal barrier coating. TMF t ests were performed with different temperature-strain phasing and diff erent applied strain levels to vary the imposed strain range on the co ating and thus separate strain dependence of life from oxidation effec ts. Results for a single crystal superalloy coated with an EB-PVD yttr ia-stabilized zirconia layer showed that as the compression on the coa ting at minimum temperature was increased the cycles to spall decrease d, following a power law dependence on total strain range. (C) 1998 El sevier Science S.A. All rights reserved.