To investigate the effects of fusing conditions on the microstructures and on fatigue properties of thermally sprayed coating, three types of thermally sprayed specimen with different heating periods in the fusing process were prepared. Rotational bending fatigue tests and characterization of coating microstructures were carried out. By using a vacuum furnace for fusing, it is possible to get sprayed coating with very little porosity and high mechanical properties. Heating time in the fusing process strongly affects the fatigue properties the longer the heating time, the lower the fatigue strength. This is because longer heating process induces a segregation of the chromium compound in the coated microstructures. In order to achieve higher fatigue strength, shorter length fusing was performed by an induction heating system. However, the fatigue strength of the specimen is much lower than that of the vacuum furnace fused specimen. This is because a delamination between the coating layer and the substrate occurred during the fatigue process and the fatigue crack started at the newly created surfaces at the substrates.
