A review on atom probe and correlative microscopy studies of corrosion in nickel-based superalloys

This article discusses challenges faced in the development of new Ni-based superalloys for applications in the hottest sections of turbine engines and the use of atom probe tomography and correlative microscopy for characterization of these complex alloys with regards to microstructural and compositional design. The two strengthening phases Y and Y ' are introduced and the precipitation of topologically close-packed phases and their potential detrimental effects on superalloy properties are reviewed. Mechanisms of environmental degradation, namely oxidation and hot corrosion, are elucidated and recent research studies on a new phenomenon of hot corrosion at relatively low temperatures below 600 degrees C are discussed. The effect of individual alloying elements on superalloy properties is reviewed, with a focus on Mo and W. The use of atom probe in correlation with state-of-the-art microscopy, spectroscopy and diffraction techniques to study and understand oxidation and corrosion of Ni-based superalloys, including crack tip investigations, is presented.

Automated summary

This article discusses the challenges faced in developing new Ni-based superalloys for the hottest sections of turbine engines and the use of atom probe tomography and correlative microscopy to characterize these complex alloys. The article introduces the strengthening phases Y and Y ', reviews the precipitation of topologically close-packed phases and their detrimental effects on superalloy properties, and explains mechanisms of environmental degradation. It also explores recent research on a new phenomenon of hot corrosion at low temperatures, and reviews the effects of individual alloying elements on superalloy properties, with a focus on Mo and W. The use of atom probe in correlation with advanced microscopy techniques to study oxidation and corrosion of Ni-based superalloys is also presented.