材料期刊网

Thermomechanical fatigue (TMF) is a major life limiting factor for gas turbine blades. In this study, the failure behavior of NiCrAlY overlay coated nickel-based superalloy M963 was investigated under out of phase (OP) TMF. All tests were carried out under mechanical strain control with a cyclic period of 200 s. Results revealed that the fatigue life of high velocity oxygen fuel spraying (HVOF) coated specimen was longer than that of air plasma spraying (APS) coated one, but shorter than that of bare superalloy M963 at a given strain range. It was found that cracking process in the APS coating was different from that in the HVOF coating, which was shown by the sketches to understand the crack initiation and propagation behavior.