About this Abstract |
| Meeting |
11th International Symposium on Superalloy 718 and Derivatives 2026: Legacy, Innovations, and Future Directions
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| Symposium
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Superalloy 718 and Derivatives 2026: Legacy, Innovations, and Future Directions
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| Presentation Title |
Investigation on the Long-Term Aging
Microstructure Evolution of Cobalt-Based Superalloy ECY768
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| Author(s) |
Zhicheng Wang, Hailong Qin, Haijing Zhou, Jinli Xie |
| On-Site Speaker (Planned) |
Zhicheng Wang |
| Abstract Scope |
Based on cobalt-based superalloy ECY768, the as-cast microstructure and the structure evolution mechanism during the long aging process, especially the carbide evolution mechanism.The results show that there are a large number of skeletal MC carbides rich in Ta and Ti and layered M7C3 carbides rich in Cr, Co distributed in the inter-dendritic region of the as cast ECY768 alloy, and their content is both about 4%. In addition, a small amount of granular M23C6 carbides rich in Cr, Co are dispersed in the matrix. A large number of stacking faults are formed in the as-cast matrix.
After aging at 900 ℃ for 200-1500 hours, there is no significant change in the type of carbides in the alloy. The main change is the slight degradation and decomposition of MC, and significant degradation and decomposition of metastable M7C3. At the same time, a large number of small granular M23C6 and chain like M23C6 precipitate from the matrix, and they all have a clear orientation relationship with the matrix: [110] M23C6 //[110]matrix, (111) M23C6 //(111) matrix. After aging, a large number of stacking faults are formed in the matrix, and fine granular M23C6 and chain-like M23C6 alloys are precipitated along the stacking faults in the alloy. The Cr element discharged from the degradation decomposition of M7C3 during the long aging process is enriched near the fault, creating conditions for the formation of chain and fine dispersed M23C6. |
| Proceedings Inclusion? |
Definite: At-meeting proceedings |