Fig. 5: Elemental diffusion between the film and substrate.

a XRD analysis of the substrate (after removing the sintered CMC film) shows that the W element in the CMC film diffuses into the substrate of Inconel 625 superalloy since the peak of WO3 appears and the peaks of [Ni,Fe] and [Cr,Fe] shift to a smaller diffraction angle. b The tightly packed interfaces in the SEM images with permeable grayscale confirm elemental diffusion.