Size-dependent dislocation–twin interactions
- Zhejiang Univ., Hangzhou (China)
- Univ. of Vermont, Burlington, VT (United States)
Dislocation–twin interactions critically control the plastic deformation and ultrahigh strength of nanotwinned metals. In this paper, we report a strong twin-thickness dependence of dislocation–twin interaction mechanisms from the tensile deformation of face-centered cubic metallic nanocrystals by in situ nanomechanical testing. Direct observations at atomic scale reveal that the predominant dislocation–twin interaction abruptly changes from dislocation transmission on the {111} slip planes to the unusual (100) slip plane of the twin, when the twin thickness is smaller than 4 layers. Using atomistic simulations, we find that the energy barrier for {100} slip transmission mechanism gradually decreases, with decreasing twin thickness, below the energy level required for normal (111) slip transmission, which remains identical for all twin sizes. Our in situ observations and simulations provide atomistic insights into a fundamentally new mechanism of plasticity in nanotwinned metals, down to the lowest twin size limit.
- Research Organization:
- Univ. of Vermont, Burlington, VT (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; National Natural Science Foundation of China (NSFC); Zhejiang Kechuang New Materials Research Institute; National Science Foundation (NSF)
- Grant/Contract Number:
- SC0016270; 51771172; 51701179
- OSTI ID:
- 1601109
- Alternate ID(s):
- OSTI ID: 1529418
- Journal Information:
- Nanoscale, Vol. 11, Issue 26; ISSN 2040-3364
- Publisher:
- Royal Society of ChemistryCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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