The objective of this work was to address the effect of 815 °C exposures on the chemistry of interior grain boundaries and associated minor phases from the fatigued volume of tested notched low cycle fatigue (NLCF) specimens of an advanced powder metallurgy superalloy ME3, which is used in turbine disk applications. Prior to NLCF testing at 704 °C in air, selected ME3 specimens were pre-exposed at 815 °C for exposures times up to 2,020 h to capture projected service conditions for the turbine disk rim. Structure, compositions and size distributions of minor phases, including MC carbides, M23C6 carbides, M3B2 borides and sigma, were identified. Minor phase and grain boundary chemistry for various conditions were evaluated with atom probe tomography and high resolution x-ray energy-dispersive spectroscopy.
Published: July 21, 2023
Citation
Sudbrack C.K., L.J. Evans, A. Garg, D.E. Perea, and D.K. Schreiber. 2016.Characterization of Grain Boundaries and Associated Minor Phases in Disk Alloy ME3 Exposed at 815 °C. In Proceedings of the 13th International Symposium on Superalloys (Superalloys 2016), September 11-15, 2016, Seven Springs, PA, edited by M. Hardy, et al, 927-936. Pittsburgh, Pennsylvania:TMS (The Minerals, Metals & Materials Society).PNNL-SA-116949.