|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Computational Thermodynamics and Kinetics
||Construction of Grain Boundary “Phase” Diagrams with Atomistic Simulation
||Shengfeng Yang, Naixie Zhou, Jian Luo
|On-Site Speaker (Planned)
The formation of interfacial phases at grain boundaries (GBs) and the occurrence of GB phase-like (complexion) transitions can affect the microstructural development and materials properties. In this study, we first modify a genetic algorithm to predict GB atomic structure by effectively searching for the lowest-energy configuration through the energy landscape at T=0K. Subsequently, a hybrid molecular dynamics and Monte Carlo method is implemented to predict equilibrium GB structures and transitions at finite temperatures. The results from atomistic simulations are used to construct GB “phase” diagrams, which reveal the GB excess, effective interfacial width, structural disorder, and GB diffusivity as functions of the bulk concentration and temperature. Examples of alloys (Mo-Ni) and ceramics (Y2O3-stablized ZrO2, perovskite oxides) will be discussed. The influences of GB complexion formation and transition on the mechanical and other properties are studied. The atomic simulation results are critically compared with density functional theory calculations and experimental observations.
||Planned: Supplemental Proceedings volume