Abstract
Molecular dynamics simulations have been performed to investigate a role of grain boundary region in deformation of nano-polycrystalline material. For three Al nano-crystal models with different mean grain sizes which consist of nearly 600,000 atoms, we perform uniaxial tensile test in two different tensile rate. As the result, the smaller mean grain size is, the smaller the value of the maximum load is. This mechanical property is against the Hall-Petch relation. Equivalent strain in atomic scale shows that the behavior of grain boundary region have a decisive role for many macroscopic properties bacause of large proportion of the grain boundary compared to ordinary porycrystalline materials.
