| About this Abstract |
| Meeting |
MS&T22: Materials Science & Technology
|
| Symposium
|
Integration between Modeling and Experiments for Crystalline Metals: From Atomistic to Macroscopic Scales IV
|
| Presentation Title |
A Grain Boundary Dislocation-density-based Crystal Plasticity Model for FCC Nanocrystalline Metals |
| Author(s) |
Jonathan Cappola, Jian Wang, Lin Li |
| On-Site Speaker (Planned) |
Jonathan Cappola |
| Abstract Scope |
A dislocation-density-based crystal plasticity model for nanocrystalline FCC metals is developed based on the thermally-activated mechanism of dislocations depinning from grain boundaries (GBs). Dislocation slips originating from GB sources are assumed to be the controlling deformation mechanism with the dislocation density being formulated as a boundary term and subsequently smeared over the grain volume uniformly. This leads to the kinematic enforcement of grain-uniform plastic deformation. Dislocation density evolution thereby involves the creation of mobile dislocations from GB ledges, and recovery via diffusion. This model allows for the evolution of the GB character, related to initial processing/production, to be computed as a direct result of dislocation-mediated plasticity. The influence of initial dislocation density distribution, along with its evolution, is investigated to in context of softening/hardening behaviors observed in bulk nanocrystals, the breakdown of Hall-Petch, and the effect of processing routes on the resulting bulk nanocrystals' mechanical properties. |