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Title: Effects of temperature on surface-controlled dislocation multiplication in body-centered-cubic metal nanowires

Journal Article · · Computational Materials Science

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
Citation Metrics:
Cited by: 3 works
Citation information provided by
Web of Science

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Figures / Tables (10)