|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Interface-driven Phenomena in Solids: Thermodynamics, Kinetics and Chemistry
||Zener Pinning of Grain Boundary Migration in Immiscible Nano-crystalline Alloys
||Raj K. Koju, K. A. Darling, L. J. Kecskes, Yuri Mishin
|On-Site Speaker (Planned)
The Zener model of grain boundary pinning by small precipitates is reviewed starting from the original version to later extensions. The model is tested by atomistic computer simulations for the immiscible Cu-Ta system, in which nanometer-scale Ta clusters precipitate inside the grains and at grain boundaries. The simulations utilize an angular-dependent interatomic potential, molecular dynamics and Monte Carlo simulations over a range of temperatures and alloy compositions. Interactions of Ta clusters with individual grain boundaries driven by applied shear stresses and capillary forces provide estimates of the pinning stress that compare well with predictions of the Zener model. A similarly good agreement is found for ensembles of grain boundaries in a nano-crystalline Cu-Ta alloy. The results provide evidence that the experimentally found extraordinary grain size stabilization in nano-crystalline Cu-Ta alloys is dominated by the kinetic factor associated with the Zener pinning effect.
||Planned: A print-only volume