About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
High-Entropy Materials: Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond VI
|
| Presentation Title |
Molecular dynamic studies of strain rate effects on screw dislocation mobility and glide mechanisms in bcc complex concentrated alloys
|
| Author(s) |
Subhendu Chakraborty, Liang Qi |
| On-Site Speaker (Planned) |
Liang Qi |
| Abstract Scope |
A major gap exists between the critical resolved shear stress (CRSS) predicted by molecular dynamics (MD) simulations and the experimentally observed yield stress in BCC metals. This discrepancy is largely attributed to the high strain rates inherent to standard MD. In this study, we investigate screw dislocation mobility in BCC metals under low strain rates using hyperdynamics, an accelerated MD technique. A novel collective variable is developed to track the dislocation core during glide. We present results for pure Nb and Mo, as well as the influence of alloying elements on screw dislocation mobility in BCC complex concentrated alloys. Our findings reveal that strain rate and dislocation line length significantly impact the dominant migration mechanisms, providing new insights into rate-limiting steps in dislocation motion at realistic timescales. These results bridge the gap between atomic-scale simulations and experimental behavior in complex concentrated BCC alloys. |