Abstract
The changes in ATI® 718Plus™ (718Plus) superalloy microstructure after high-temperature long-term exposure (850 °C/4000 h/air) were characterized by two- and three-dimensional imaging techniques. The 718Plus microstructure consists of a γ-matrix strengthened by coherent γ′-phase and plate-like η-phase at grain boundaries. The η-phase analysis showed the presence of δ-phase stacking faults within it, along with fluctuations of chemical composition within these defects. Applied thermal exposure resulted in an increased amount of δ-, η-phases and formation of topologically close-packed phases. One of them was identified by electron diffraction as trigonal μ-phase. However, the difference in size and morphology revealed via tomographic reconstruction indicates that the formation of other topologically close-packed phases is possible. The μ-phase was enriched in Mo, Co, Fe and Cr, which causes their depletion in the γ-matrix and may detrimentally affect the superalloy mechanical properties.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
