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Multi-Scale Crystal Plasticity Model of Creep Responses in Nickel-Based Superalloys
Shahriyar Keshavarz1, Carelyn E Campbell1, Andrew C E Reid1
1Materials Science Division, Thermodynamics and Kinetics Group, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Materials (Basel, Switzerland)
|July 9, 2022
Summary
This study models creep in nickel-based superalloys using multi-scale crystal plasticity. The approach accurately predicts material behavior across various conditions by linking microstructural details to macroscopic responses.
Area of Science:
- Materials Science
- Mechanical Engineering
- Computational Modeling
Background:
- Nickel-based superalloys are critical for high-temperature applications, but their complex microstructures and creep behaviors are challenging to model.
- Understanding creep mechanisms, including dislocation interactions and microstructural evolution, is essential for predicting material performance.
Purpose of the Study:
- To develop and validate a multi-scale crystal plasticity finite element (CPFE) model for simulating the creep behavior of two-phase γ-γ' nickel-based superalloys.
- To link microstructural features (size, volume fraction, shape) and physical parameters to the macroscopic mechanical response of these alloys.
Main Methods:
- A multi-scale framework was employed, integrating sub-grain and homogenized scales within a CPFE platform.
- The sub-grain scale used a dislocation density-based constitutive model, while the homogenized scale employed an activation energy-based crystal plasticity model.
- The model explicitly incorporated γ-γ' morphology and considered dislocation mechanisms like Anti-Phase Boundary (APB) shearing and glide-climb.
Main Results:
- The developed homogenized model significantly accelerates computation while maintaining reliable accuracy.
- The model successfully captures the thermo-mechanical behavior, orientation dependence, and tension-compression asymmetry of nickel-based superalloys.
- Validation against experimental data for diverse compositions, temperatures, and orientations confirmed the model's predictive capabilities.
Conclusions:
- The multi-scale CPFE approach provides an effective framework for modeling creep in nickel-based superalloys.
- The parameterized homogenized model offers an efficient yet accurate method for predicting alloy performance under various conditions.
- This work advances the understanding and prediction of superalloy behavior, crucial for designing advanced high-temperature components.
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