Effects of temperature on surface-controlled dislocation multiplication in body-centered-cubic metal nanowires
- Univ. of Connecticut, Storrs, CT (United States)
Recent computational studies revealed that screw dislocations in body-centered-cubic (bcc) metal nanowires can self-multiply through cross-slip near the free surface. This unique process was termed surface-controlled dislocation multiplication (SCDM). In bcc metals, screw dislocation motion and its cross-slip behavior are often related to thermally activated processes; due to this relation, SCDM is expected to be highly temperature-sensitive. In this study, therefore, we investigated how temperature influences the SCDM in bcc molybdenum and niobium nanowires using atomistic simulations. Regardless of the difference in lattice resistance at a given temperature, both systems show similar trends of critical shear stress of SCDM with respect to temperature. Further, the temperature dependence was found to be divided into three different regimes; (1) lattice-resistance-dominant; (2) segmentation-dominant; (3) steady-state segmentation. The presence of these three regimes will be discussed in terms of the temperature-dependence of the lattice resistance and the dynamics of dislocation segmentation in the nano-scale volume. Our results provide a fundamental understanding of screw dislocation behavior in bcc metals at the nanometer scale and varying temperatures.
- Research Organization:
- Univ. of Connecticut, Storrs, CT (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division; USDOE
- Grant/Contract Number:
- SC0018895
- OSTI ID:
- 1599643
- Alternate ID(s):
- OSTI ID: 1542675
- Journal Information:
- Computational Materials Science, Vol. 168, Issue C; ISSN 0927-0256
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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