| About this Abstract |
| Meeting |
2019 TMS Annual Meeting & Exhibition
|
| Symposium
|
Gamma (FCC)/Gamma-Prime (L12) Co-Based Superalloys III
|
| Presentation Title |
M-14: Effects of Cr and Al Additions on the Microstructure and Mechanical Properties of Co-Ti-W Based Alloys |
| Author(s) |
Boryung Yoo, Hye Ji Im, Jae-Bok Seol, Pyuck-Pa Choi |
| On-Site Speaker (Planned) |
Boryung Yoo |
| Abstract Scope |
We report on the design and characterization of 𝛾/𝛾'-strengthened Co-12Ti-4W-based alloys for high-temperature applications. Using atom probe tomography, it is found that Co, Cr, and Al atoms partition to 𝛾 phase while Ti, W partition to 𝛾'. The addition of W to the Co-12Ti reference alloy results in an increased 𝛾' volume fraction due to strong partitioning of W to 𝛾'. Moreover, the addition of Cr and Al to Co-12Ti-4W alloys leads to a dramatically increased 𝛾' volume fraction of up to about 80% and a decreased 𝛾/𝛾' lattice misfit close to 0.5%. Alloying of W, Cr, and Al enhances the thermal stability of the 𝛾' phase, as confirmed by differential scanning calorimetry. All Co-12Ti-4W based alloys also show a yield stress anomaly and the yield stress of Co-12Ti-4W-4Al shows a huge increase above 600oC surpassing that the high-temperature strength of Co-Al-W and conventional Co-based superalloys. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |