Li Qing-Jie, Li Ju, Shan Zhi-Wei, Ma Evan
Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA.
Department of Nuclear Science and Engineering and Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
Phys Rev Lett. 2016 Oct 14;117(16):165501. doi: 10.1103/PhysRevLett.117.165501. Epub 2016 Oct 11.
Under ultrahigh stresses (e.g., under high strain rates or in small-volume metals) deformation twinning (DT) initiates on a very short time scale, indicating strong spatial-temporal correlations in dislocation dynamics. Using atomistic simulations, here we demonstrate that surface rebound of relativistic dislocations directly and efficiently triggers DT under a wide range of laboratory experimental conditions. Because of its stronger temporal correlation, surface rebound sustained relay of partial dislocations is shown to be dominant over the conventional mechanism of thermally activated nucleation of twinning dislocations.
