About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advances in the State-of-the-Art of High Temperature Alloys
|
| Presentation Title |
Precipitation Behavior of Topologically Closed-Packed Phases in TMS-238 at 1150 °C |
| Author(s) |
Shizuna Oyano, Satoshi Utada, Chihiro Tabata, Ayako Ikeda, Toshio Osada, Kyoko Kawagishi, Shinsuke Suzuki |
| On-Site Speaker (Planned) |
Shizuna Oyano |
| Abstract Scope |
TMS-238 is one of the best Ni-based single-crystal superalloys with excellent high-temperature properties. However, it is more expensive than other commercial alloys as it contains 5 wt.% Ru to prevent precipitation of topologically closed-packed (TCP) phases. In this study, prolonged high-temperature ageing tests were performed on TMS-238 at 1150 °C. The area fraction of TCP phase in dendritic core was higher than that in interdendritic area. Location specific reaction rate constants were determined by fitting the data into Johnson–Mehl–Avrami (JMA) equation. The reaction rate constant of the interdendritic area was greater than that of the dendritic core. These mean that the TCP fraction is larger at the dendritic core, however, interdendritic area requires a shorter time to reach the equilibrium. Creep failure usually starts from interdendritic areas; therefore, evaluation of local TCP precipitation behavior is important when applying alloys with high magnitude of micro segregation. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Temperature Materials, Phase Transformations, Copper / Nickel / Cobalt |