Phase-field modeling of microstructural pattern formation during directional solidification of peritectic alloys...

Area of Science:

• Materials Science
• Solidification Science
• Computational Materials Science

Background:

• Peritectic alloys exhibit complex microstructures during directional solidification.
• Microstructure formation depends on the temperature gradient/growth rate ratio (G/v(p)).
• Morphological stability of solid phases dictates growth patterns, from cellular-dendritic to layered structures.

Purpose of the Study:

• To develop and utilize a phase-field model for peritectic solidification.
• To investigate the formation of layered and island microstructures.
• To understand the transition dynamics between different peritectic growth morphologies.

Main Methods:

• Development of a phase-field model incorporating nucleation.
• Numerical simulations of peritectic solidification under varying conditions.
• Analysis of microstructure evolution, phase spreading dynamics, and morphology transitions.

Main Results:

• The model successfully reproduces observed peritectic microstructures, including bands and islands.
• Simulations reveal a constant acceleration in the lateral spreading of the peritectic phase.
• The study elucidates the morphology transition from islands to bands as a function of nucleation and growth dynamics.

Conclusions:

• Phase-field modeling provides crucial insights into peritectic solidification mechanisms.
• Nucleation and growth interplay governs microstructure formation in stable regimes.
• The findings predict growth morphologies relevant for larger-scale solidification processes.