|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Deformation and Transitions at Interfaces
||Strong Nonlinear Increase in the Yield Strength Due to Solute Segregation at Grain Boundaries in FCC Nano-crystalline Metals
||Valery Borovikov, Mikhail Mendelev
|On-Site Speaker (Planned)
We used Monte Carlo and molecular dynamics simulations to study the effect of Cu solute atoms segregated at grain boundaries (GB) in nano-crystalline Ag on dislocation nucleation under applied tensile stress. We observed strongly non-linear increase in the yield stress with increasing solute concentration. The detailed analysis of the simulation data revealed that in the pure system under applied stress the dislocations nucleate from both the E units at the GBs and the triple junctions. Addition of solutes halts the dislocation nucleation and emission from the E units at the GBs, but the triple junctions are still able to emit the dislocations. Once all favorable segregation sites at the E units at the GBs are filled, the solutes segregate at the triple junctions and the yield stress increases dramatically. Yet, at some solute concentration the yield stress reaches a maximum and then decreases with further increase of the solute concentration.