Large-scale atomistic simulations of anisotropic plastic deformation in bulk nanostructured metals

Tsuru, Tomohito   ; Aoyagi, Yoshiteru*; Kaji, Yoshiyuki  ; Shimokawa, Tomotsugu*

The plastic deformation of ultrafine-grained metals was investigated by large scale atomistic simulations. Some polycrystalline models were constructed and the uniaxial tension and compression were applied to the polycrystalline aluminum and copper models. It is found that yield stress is strongly influenced by the number of intragranular dislocation sources, i.e., dislocation density. The Bauschinger effect of bulk nanostructured metals (BNM) is caused by the change in dislocation density in the process of forwarding and backwarding deformation. Additionally, the yield stresses of tensile and compressive deformation have some sort of plastic anisotropy. BNM aluminum shows more significant anisotropy than BNM copper.