Author(s)

K.M. Ostolaza, J.L. Valles, J. Bressers & A. Sanchez-Pascual

Abstract

Evolution of a nickel-aluminide diffiision coating on a single crystal superalloy under IMF K.M. Ostolaza^, J.L. Valles*, J. Bressers*, A. Sanchez-PascuaP "Institute for Advanced Materials, Joint Research Centre, P.O. Box 2, 1755 ZG Petten, The Netherlands *>INTA, Materials Department, Madrid, Spain Abstract Experimental evidence is provided, using X-ray techniques, of the presence of an LlQ phase under certain conditions in the nickel- aluminide coatings protecting specimens of a single crystal Ni- based superalloy tested under thermomechanical fatigue. This phase, which is related to the occurrence of a martensitic transformation, is shown to have an effect on the stress required for crack initiation in the coating. Introduction Single crystals of nickel-base superalloys are widely used as aircraft turbine blades, due to their excellent high temperature strength and creep resistance. Those components are usually protected by the application of a coating, whic

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