| About this Abstract |
| Meeting |
2024 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Stability in Extreme Environments II
|
| Presentation Title |
Effects of Microstructural Variance on Edge Dislocation Mobility and Pinning in Nickel Superalloys at High Temperatures |
| Author(s) |
Lukas Metzger, Stephen Taller |
| On-Site Speaker (Planned) |
Lukas Metzger |
| Abstract Scope |
Nickel-based superalloys are precipitation hardened alloys considered for use in high-temperature applications due to their excellent mechanical properties as a result of their γ′, γ″, and δ phases. The interactions between the primary strengthening phase in superalloy 718, γ″ precipitates, and stress-driven mobile edge dislocations were examined using molecular dynamics simulations. Each dislocation movement simulation cell consisted of an FCC Ni lattice, an edge dislocation, and a γ″ precipitate up to 10 nm in diameter oriented either parallel, perpendicular, or orthogonal to the Burgers vector with a constant shear rate applied. Simulations results demonstrated the presence of a strain field surrounding the precipitate, its influence on dislocation movement, and a decrease in the peak shear stress to de-pin dislocations with increasing temperature up to 873K. Varying the orientation of the precipitate demonstrated drastic differences in dislocation bowing behavior and resulting obstacle strength coefficients that correlated qualitatively with tensile properties. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Temperature Materials, Computational Materials Science & Engineering, Mechanical Properties |