Unravelling the physics of size-dependent dislocation-mediated plasticity.

ABSTRACT: Size-affected dislocation-mediated plasticity is important in a wide range of materials and technologies. Here we develop a generalized size-dependent dislocation-based model that predicts strength as a function of crystal/grain size and the dislocation density. Three-dimensional (3D) discrete dislocation dynamics (DDD) simulations reveal the existence of a well-defined relationship between strength and dislocation microstructure at all length scales for both single crystals and polycrystalline materials. The results predict a transition from dislocation-source strengthening to forest-dominated strengthening at a size-dependent critical dislocation density. It is also shown that the Hall-Petch relationship can be physically interpreted by coupling with an appropriate kinetic equation of th

SUBMITTER: El-Awady JA 

PROVIDER: S-EPMC4354076 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature