| About this Abstract |
| Meeting |
2019 TMS Annual Meeting & Exhibition
|
| Symposium
|
Gamma (FCC)/Gamma-Prime (L12) Co-Based Superalloys III
|
| Presentation Title |
Partitioning Preferences of Alloying Elements and their Effect on the Stability of the γʹ/L1<sub>2</sub>-phase in Co-base Superalloys |
| Author(s) |
Li Wang, Yuzhi Li, Michael Oehring, Uwe Lorenz, Florian Pyczak |
| On-Site Speaker (Planned) |
Florian Pyczak |
| Abstract Scope |
γʹ/L1<sub>2</sub>-hardened Co-base superalloys show a number of dissimilarities when compared with Ni-base superalloys. The Co<sub>3</sub>(Al,W) L1<sub>2</sub>-structure is prone to decompose into B2 or D0<sub>19</sub> structures. The latter transformation seems to be preceded by stacking fault activity locally changing the atomic order of the lattice. Whether B2 or D0<sub>19</sub> is the preferred transformation product depends on the presence of additional alloying elements with Ti stabilising B2 and Mo or Nb promoting D0<sub>19</sub>. Also the partitioning preferences between matrix and γʹ phase and also the different atomic sites in the γʹ/L1<sub>2</sub> structure show certain peculiarities. One example is the tendency of Cr to enrich in the matrix phase but preferring the same atomic sites when found in the L1<sub>2</sub> structure as elements with a tendency to enrich in γʹ like W, Ti or Ta. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |