Phase-field-crystal study of solute trapping.

Area of Science:

• Materials Science
• Computational Physics
• Physical Chemistry

Background:

• Understanding solute trapping is crucial for controlling alloy properties.
• Existing models often simplify the complex dynamics at the crystal-melt interface.

Purpose of the Study:

• To investigate solute trapping in binary alloys by incorporating two time scales into the phase-field-crystal model.
• To analyze the impact of diffusive and wavelike dynamics on solute trapping properties.
• To compare model predictions with established theories.

Main Methods:

• Utilized a phase-field-crystal model for binary alloys.
• Incorporated two distinct time scales to represent different dynamics.
• Simulated scenarios with purely diffusive dynamics.
• Simulated scenarios with wavelike dynamics in density and concentration fields.

Main Results:

• Diffusive dynamics align with the Kaplan-Aziz model, showing the segregation coefficient (K) approaching unity at infinite velocity.
• Wavelike dynamics introduce a new kinetic regime, predicting complete solute trapping at a finite velocity.
• The study demonstrates a transition in solute trapping behavior based on the nature of interface dynamics.

Conclusions:

• The phase-field-crystal model with dual time scales effectively captures diverse solute trapping behaviors.
• Wavelike dynamics play a significant role in solute trapping, enabling complete trapping at finite velocities.
• This research provides insights into controlling alloy solidification and microstructure through interface kinetics.