|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Advances in Multi-Principal Elements Alloys X
||Revealing strengthening mechanisms in refractory multi-principal elements alloys
||Xinyi Wang, Francesco Maresca, Penghui Cao
|On-Site Speaker (Planned)
Body-centered cubic (bcc) refractory multi-principal alloys (r-MPAs) have been the subject of extensive research over the last decade because of their potential as candidate materials for high-temperature applications. In contrast to many bcc pure metals and dilute alloys, r-MPAs show a gradual decrease of strength with increasing temperature and even a strength plateau in the intermediate temperature range. In this work, we investigate the mobility and slip process of edge and screw dislocations in NbMoTaW r-MPA at various applied stresses and temperatures by using a machine learning interatomic potential with atomistic simulations. Our results show that compositional inhomogeneity along the dislocation line promotes kink nucleation, cross-kink formation and pinning. Moreover, our simulations confirm that local chemical inhomogeneity slows down edge dislocation motion, whose sluggish mobility considerably contributes to the high-temperature strength of bcc. Finally, we reveal the effect of chemical short-range order on the above screw and edge strengthening mechanisms.
||High-Entropy Alloys, Modeling and Simulation, Mechanical Properties