|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Computational Thermodynamics and Kinetics
||A Discrete Dislocation Model of Creep in Single Crystals
||M. Rajaguru, Shyam M. Keralavarma
|On-Site Speaker (Planned)
Failure due to creep is a design limiting issue for metallic materials used in several critical high-temperature applications. While phenomenological models such as power laws are extensively used by designers, there is little fundamental understanding of the microscopic origin of these scaling relations. Here, we modify a widely used two-dimensional discrete dislocation dynamics framework for plasticity to perform creep simulations at elevated homologous temperatures in bulk single crystalline materials, using a unit cell model. Creep results from the thermally activated glide of discrete dislocations on multiple slip systems through an array of obstacles. Several modes of thermal activation such as obstacle cutting and obstacle bypass by jog formation are considered. A kinetic Monte Carlo algorithm is used to predict the overall strain rates and the results are compared against experimentally known ranges for the strain rates, activation energies and stress exponents for creep.
||Planned: A print-only volume