|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Computational Thermodynamics and Kinetics
||A Universal Discrete Dislocation Model for Thermal Activation and Diffusion-assisted Climb
||Run Zhu, Srinath Chakravarthy
|On-Site Speaker (Planned)
Given that thermal activation and climb of dislocation contribute significantly to high temperature plastic behavior, a thorough understanding of dislocation motion is extremely critical. A new discrete dislocation model is presented to determine equilibrium configurations of dislocations as a function of temperature and strain rate. The thermal activation mechanisms and diffusion-assisted climb are incorporated at appropriate time scales. Also, a new universal model for diffusion assisted climb is presented that is applicable and accurate for arbitrary choice of time scales. It involves solution of an auxiliary mechanical-diffusion boundary value problem by treating dislocations as continuous source/sink of vacancies. It enables computing the rate of climb of dislocations at arbitrary temporal scales. Several applications are shown for our new model from tension/bending of micron sized samples, to creep and fatigue at high temperature.
||Planned: Supplemental Proceedings volume