About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Verification, Calibration, and Validation Approaches for Mechanical Modeling of Metals
|
| Presentation Title |
Predicting Thermal Creep Deformation in Metals via a Strain Gradient Crystal Plasticity Finite Element Model including Diffusion-Assisted Dislocation Climb and Grain Boundary Sliding |
| Author(s) |
Sajjad Izadpanah, Marko Knezevic |
| On-Site Speaker (Planned) |
Sajjad Izadpanah |
| Abstract Scope |
Accurate prediction of creep deformation in polycrystalline metals requires capturing the competing contributions of dislocation glide, diffusion-assisted dislocation climb, and grain boundary (GB) sliding — mechanisms that are strongly coupled and inherently microstructure-sensitive. This study develops an advanced crystal plasticity finite element (CPFE) framework incorporating the kinematics of diffusion-assisted dislocation climb together with a cohesive zone formulation for GB sliding, enabling physically based prediction of creep behavior. A core-diffusion hardening law accounts for solute diffusion around pinned dislocation cores, capturing obstacle bypass mechanisms and strain rate sensitivity during creep. The framework can resolve geometrically necessary dislocations and their associated long-range internal stresses through a nonlocal strain-gradient formulation, enabling accurate representation of spatial heterogeneity in dislocation structures and internal stresses, particularly near grain boundaries where creep deformation localizes. The framework is applied to simulate creep deformation in Grade 91 ferritic-martensitic steel across temperatures and stress levels, benchmarking predictions against experimental data. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Other, Other, Other |