Effects of Grain Boundary Disorder on Dislocation Emission
Ames Laboratory; Materials Science and Engineering
Ames Laboratory, Materials Science and Engineering
It was recently reported that segregation of Zr to grain boundaries (GB) in nanocrystalline Cu can lead to the development of disorder in the intergranular structure (Khalajhedayati et al., 2016; Khalajhedayati and Rupert, 2015). In this study we employ atomistic computer simulations to investigate how this disorder affects dislocation nucleation from the GBs under applied stress. It was found that a fully disordered grain boundary structure suppresses dislocation emission and significantly increases the yield stress. Depending on the solute concentration and heat-treatment, however, partial disorder may also occur and this aids dislocation nucleation rather than suppressing it, reducing or eliminating the strengthening effect.
DOE Contract Number(s)
Department of Energy Subject Categories
36 MATERIALS SCIENCE
Iowa State University Digital Repository, Ames IA (United States)