Study by complementary X-ray techniques of in-depth microstructure in Ni-based superalloys after Pt diffusion treatment

The in-depth microstructure changes in nickel-based superalloy due to prior Pt diffusion treatment have been analyzed using complementary X-ray methods. X-Ray diffraction shows the presence of a three-phase system in the entire treated thickness for thick Pt coatings (10 μm). Surface probing by X-ray absorption spectroscopy reveals the presence of a Pt-based phase at the top surface. For thinner Pt coatings (5 μm), X-ray diffraction and absorption techniques reveal a homogeneous in-depth microstructure associated with the γ/γ′ Ni-based superalloy phases. Results obtained for these two thickness values are well correlated with in-depth Pt concentration profiles determined by energy-dispersive X-ray analysis (EDX).