|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Advances in Multi-Principal Elements Alloys X
||Atomistic modeling of dislocations in refractory high-entropy alloys
||Sheng Yin, Jun Ding, Mark Asta, Robert Ritchie
|On-Site Speaker (Planned)
This presentation is focused on dislocation core properties, mobility and effects of short-range order (SRO) in bcc refractory HEAs. Using density-functional-theory with molecular-dynamics, we investigate the distribution of dislocation core properties in MoNbTaW RHEAs, the mobility of screw/edge dislocations over a wide temperature range, and the influence of SRO. The average core energies are found to be larger than those in corresponding constituent bcc metals, and are relatively insensitive to SRO, although SRO induces diffuse antiphase boundaries which serve to narrow the distribution of dislocation core energies and decrease their spatial heterogeneity. The mobility of edge dislocations is found to be enhanced by the presence of SRO, whereas the corresponding mobility of screws is lessened, although the influence of SRO becomes attenuated at increasing temperature. Regardless of the presence of SRO, a unique cross-slip locking mechanism is observed for the motion of screws, which provides for additional strengthening.
||High-Entropy Alloys, Computational Materials Science & Engineering,