Oxidation-Related Microstructural Changes at a Crack Tip in Waspaloy After Elevated-Temperature Dwell-Fatigue Testing

摘要

Using advanced aberration-corrected scanning transmission electron microscopy coupled with high-resolution energy-dispersive spectroscopy techniques, transitions to microstructure and composition occurring at a grain boundary (GB) crack-tip in Waspaloy after dwell-fatigue at 704 degrees C are characterized at the nano to atomic scale. The simple microstructure of this gamma/gamma ' superalloy, which enables elucidation of oxygen effect ahead of the oxide intrusion-dissolution of the precipitates fostering selective segregation of Al to the GB to form oxides-has been experimentally observed.