Crack tip dislocation activity in refractory high-entropy alloys
Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review
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Detail(s)
Original language | English |
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Article number | 108753 |
Journal / Publication | International Journal of Mechanical Sciences |
Volume | 262 |
Online published | 15 Sept 2023 |
Publication status | Published - 15 Jan 2024 |
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Abstract
Dislocation activities play an important role in the deformation and failure of refractory high-entropy alloys (RHEAs). However, the impact of chemical short-range ordering (SRO) on dislocation activities at a crack tip in RHEAs remains unclear. Here, we investigate the effect of SRO on the dislocation nucleation, propagation, and reaction at a crack tip in a body-centered-cubic (BCC) MoTaTiWZr RHEA, using a combination of molecular dynamic simulations and Monte Carlo methods. Our results indicate that this RHEA is energetically favorable to form SRO, developing a pseudo-composite microstructure with low-energy clusters (LECs), medium-energy clusters (MECs), and high-energy clusters (HECs). The HECs at the crack tip are favorable sites for dislocation nucleation whereas the MECs surrounding the HECs function as a strong matrix to stabilize the weak HECs. At elevated temperatures, the HECs near the crack tip transform to severely distorted BCC and disordered structures, which can cause the breakup, absorption, and annihilation of emitted dislocations and nucleation of new dislocations. Our work reveals the interesting role of SRO in altering the dislocation activities at the crack tip of RHEAs and suggests alternative routes for designing superior RHEAs at both room and elevated temperatures. © 2023 Elsevier Ltd.
Research Area(s)
- Dislocation annihilation, Dislocation breakup, Dislocation nucleation, Refractory high-entropy alloys, Short-range ordering
Citation Format(s)
Crack tip dislocation activity in refractory high-entropy alloys. / Chen, Shuai; Aitken, Zachary H.; Pattamatta, Subrahmanyam et al.
In: International Journal of Mechanical Sciences, Vol. 262, 108753, 15.01.2024.
In: International Journal of Mechanical Sciences, Vol. 262, 108753, 15.01.2024.
Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review