Atomistic view of plasticity in nanophase materials
The authors report the latest results of the research program designed to provide an atomistic view of the processes involved in the plastic behavior of two nanophase model materials, namely Ni and Cu. The modeled materials have average grain sizes in the range 3--12 nm and different stacking fault energies. In previous studies, they analyzed several aspects of the deformation process, including grain size dependence, temperature and stress dependence, strain rate and texture dependence, arriving at a picture of plasticity based on a competition between intra-grain and inter-grain contributions: at the smallest grain sizes, all deformation is accommodated in the grain boundaries; at higher grain sizes, they observe intra-grain dislocation activity. Analysis of the atomic configurations shows that intrinsic stacking faults are produced by motion of Shockley partial dislocations generated and absorbed in opposite grain boundaries. In Cu, they observe the stacking faults at smaller grain sizes than in Ni (8 nm in Cu, 12 nm in Ni) which is attributed to the lower stacking fault energy. Atomic displacement analysis shows that deformation starts at triple points with grain boundary sliding, followed by the creation of intra-grain partial dislocations.
- Research Organization:
- Paul Scherrer Inst., Villigen PSI (CH)
- Sponsoring Organization:
- Swiss National Science Foundation (SNSF); CONICET (Argentina)
- OSTI ID:
- 20014219
- Resource Relation:
- Conference: 1999 TMS Fall Meeting, Julia R. Weertman Symposium: Advanced Materials for the 21st Century, Cincinnati, OH (US), 10/31/1999--11/04/1999; Other Information: PBD: 1999; Related Information: In: Advanced materials for the 21st century: The 1999 Julia R. Weertman symposium, by Chung, Y.W.; Dunand, D.C.; Liaw, P.K.; Olson, G.B. [eds.], 585 pages.
- Country of Publication:
- United States
- Language:
- English
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