Atomistic simulations on size-dependent yield mechanism of ultrafine-grained metals

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

no journal, , 

Recent metal processing technique allows the effective control of grain scale and microstructure in metallic systems, improving bulk material properties. In this study, huge-scale atomistic simulations of the polycrystalline thin film containing the Frank-Read source are performed to elucidate the fundamental deformation mechanism of ultrafine-grained metals. While the first plastic deformation occurs by the dislocation bow-out motion within the grain region for both models, the subsequent plastic deformation is strongly influenced by the resistance of the slip transfer by dislocation transmission through grain boundaries. Subsequently, the Bauschinger effect of the ultrafine-grain metals is investigated using three-dimensional polycrystalline model with dislocation sources within the grain region.