Hierarchical dislocation nucleation controlled by internal stress in nanocrystalline copper
Abstract
Dislocation nucleation is fundamental to mechanical properties of nanocrystalline (nc) materials. At grain size less than 100 nm, dislocations have been observed to nucleate predominantly from grain boundaries. Here, we report a process of dislocation generation originated hierarchically from different microstructural components in nc-copper from an atomistic simulation. We show that the sequential nucleation is dictated by the internal stress associated with the microstructural entities: First from the vertex points where internal stress is highest, next from triple junctions, and then from grain boundaries with lower internal stress. This connection suggests effective solutions for engineering mechanical properties of nc materials.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 17, 2013
- Source ID
- 10.1063/1.4811791
Entities
People
- Mo Li
- Tao Xu
- Yong-bo Guo
Organizations
- Army Research Office
- Georgia Tech
- Harbin Institute of Technology
- Tsinghua University