Molecular dynamics simulation of a glissile dislocation interface propagating a martensitic transformation

Area of Science:

• Materials Science
• Computational Materials Science
• Solid-State Physics

Background:

• The Parrinello-Rahman method is a powerful tool for molecular dynamics simulations.
• Modeling material deformation, especially with slip, is crucial for understanding material behavior.
• Martensitic transformations involve complex deformation mechanisms.

Purpose of the Study:

• To generalize the Parrinello-Rahman method to incorporate slip alongside cell deformation.
• To derive equations of motion and a microscopic expression for traction within this generalized framework.
• To simulate and analyze the nucleation and propagation of dislocation interfaces during a model transformation.

Main Methods:

• Generalization of the Parrinello-Rahman method to include slip.
• Derivation of new equations of motion.
• Introduction of a microscopic expression for traction.
• Application of Lagrangian constraints for invariant plane shear.
• Simulation of a model martensitic transformation.

Main Results:

• Successfully generalized the Parrinello-Rahman method to include slip.
• Derived equations of motion and a traction expression.
• Demonstrated the nucleation and propagation of a glissile dislocation interface.
• Validated the method's ability to model invariant plane shear characteristic of martensites.

Conclusions:

• The generalized method provides a robust framework for simulating deformation with slip.
• This approach enables detailed study of dislocation interface dynamics in transformations.
• The findings offer new insights into the mechanisms of martensitic phase transitions.