| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Hume-Rothery Symposium: Accelerated Measurements and Predictions of Thermodynamics and Kinetics for Materials Design and Discovery
|
| Presentation Title |
An Atom-Probe Tomogaphy Study of the Temporal Evolution of Concentration Retention Excesses and Depletions at gamma-f.c.c/gamma-prime-L12 Interfaces in a Ni-Al-Cr-Re Superalloy |
| Author(s) |
David N. Seidman |
| On-Site Speaker (Planned) |
David N. Seidman |
| Abstract Scope |
The coarsening kinetics of coherent gamma-prime-L12-precipitates in a Ni–10Al-8.5Cr-2Re at.% alloy aged at 973 K from 0 to 1024 h are studied utilizing atom-probe tomography and diffusion theory. The temporal evolutions of concentration retention excesses and depletions at the gamma-f.c.c/gamma-prime interfaces are presented. The compositional trajectories of both phases are presented in the Ni-Al-Cr-Re phase-diagram as represented in a tetrahedron. The gamma-prime phase is nucleated in the gamma-prime-phase field. Its composition trajectory encompasses nucleation, growth, and coarsening. The tie-line between the gamma- and gamma-prime-phases is determined by the end-point compositions of the two-phases on the two conjugate solvus surfaces. The composition trajectories of both phases are curvilinear. To explain this common phenomenon in the three Ni-based alloys (Ni-Al, Ni-Al-Cr, and Ni-Al-Cr-Re) it is necessary to include the off-diagonal terms in the diffusivity matrices, which give rise to solvent-solute and solute-solute flux couplings. |
| Proceedings Inclusion? |
Planned: |