| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Algorithm Development in Materials Science and Engineering
|
| Presentation Title |
Mechanistic Modeling of Point Diffusion in Polycrystals to Capture Different Diffusion-deformation Mechanisms |
| Author(s) |
Aritra Chakraborty, Veerappan Prithivirajan, Nathan Beets, Arul Kumar Mariyappan, Ricardo Lebensohn, Laurent Capolungo |
| On-Site Speaker (Planned) |
Aritra Chakraborty |
| Abstract Scope |
Vacancy diffusion-mediated plasticity can dominate the creep response of metals at elevated homologous temperatures and moderate stresses. In practice, diffusional flow can occur either by Coble creep (grain boundary diffusion), Nabarro–Herring creep (lattice diffusion) or dislocation creep. While standard deformation-mechanism (Ashby) maps represent the dominant governing mechanism under a given condition of stress and temperature, all the aforementioned deformation mechanisms can simultaneously be activated. In this work, we propose an advanced mechanistic model to capture both grain boundary and bulk vacancy diffusion, coupled within a full-field crystal plasticity framework that accounts for the plastic deformation mediated by dislocation motion. Kinematic coupling occurs through the chemical strain tensor having dilatational and shear strain components. Using austenitic steel as an example, we demonstrate that the framework can capture both Coble creep and Nabarro–Herring creep mechanisms as a function of microstructure, and generate the partial Ashby maps, through the full-field simulations. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, Modeling and Simulation, High-Temperature Materials |