Microstructural characterization of a Ru-containing single crystal nickel-based superalloy

Abstract

The microstructure of a Ru-containing single crystal nickel-based superalloy, which is a potential fourth generation single crystal nickel-based superalloy heat treated, has been investigated. The X-ray diffraction (XRD) results indicate that this single crystal superalloy is not a perfect monocrystal, which is comprised of many subgrains with an average neighboring misorientation difference about 0.5° and the maximum misorientation deviation about 3°; and each subgrain includes large numbers of mosaic structures with misorientation difference of 0.1°-0.2° between each other. It is found that the microstructure of the heat treated alloy is of heterogeneity, where the volume fraction of γ′ phase increases and the γ/γ′ lattice misfit decreases. It is shown that the average size of γ′ phase is 0.39 μm, the average γ′ volume fraction 70% and the average γ/γ′ lattice misfit -2.0×10 -3. The evolution of this microstructure was also briefly described. © Right.