About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Chemistry and Physics of Interfaces
|
| Presentation Title |
Tension-compression asymmetry of dislocation nucleation at interphase boundaries |
| Author(s) |
Yang Li, Yuri Mishin |
| On-Site Speaker (Planned) |
Yuri Mishin |
| Abstract Scope |
We present atomistic simulations of dislocation nucleation on the metal side of metal-nonmetal phase boundaries under applied uniaxial loads. Al/Si interfaces are used as an example, with atomic interactions described using a newly developed machine-learning interatomic potential in the moment-tensor potential (MTP) format. Under uniaxial stresses applied parallel or normal to the interface, the plastic deformation of Al starts with the nucleation of a dislocation half-loop at the interface. The stress of nucleation is significantly higher under compression than under tension, with markedly different separation widths between the Shockley partials. Analysis shows that the cause of the tension-compression asymmetry is the increase in the intrinsic stacking fault energy (ISFE) under normal compression and a decrease under normal tension. The stress effect on the ISFE is confirmed by DFT calculations and reproduced by the MTP potential. Classical interactomic potentials fail to reproduce this effect and predict incorrect tension-compression behavior. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, Mechanical Properties, Modeling and Simulation |