A Unified Microstructure-Based Constitutive Model for a Ni-Based Superalloy and Its Application in the Forging...

Area of Science:

• Materials Science
• Mechanical Engineering
• Computational Modeling

Background:

• Hot deformation of Ni-based superalloys is critical for performance but complex to model.
• Existing models often struggle to integrate microstructural evolution with macroscopic behavior.

Purpose of the Study:

• To develop a novel unified constitutive model for Ni-based superalloys.
• To systematically integrate microstructural evolution with macroscopic stress-strain response during hot deformation.
• To enhance the simulation and optimization of forging processes.

Main Methods:

• Incorporation of microstructural variables (damage, recrystallization, δ phase, grain size, dislocation density).
• Inclusion of macroscopic stress state parameters (principal stress, hydrostatic stress, Mises stress).
• Integration with the finite element method (FEM) via custom subroutines.

Main Results:

• Model prediction errors for rheological curves are less than 3%.
• Relative errors for recrystallization fraction and average grain size are below 8%.
• Demonstrated exceptional predictive accuracy in critical disk forging regions.

Conclusions:

• The unified constitutive model accurately captures microstructure evolution and stress-strain behavior.
• The FEM-integrated framework reliably simulates and optimizes forging processes.
• The model provides a robust tool for understanding and controlling high-temperature deformation in superalloys.