Molecular dynamics simulation and analysis of pre-crystallization layer between liquid and solid states.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Materials Science

Background:

• Crystallization transforms liquid's short-range order into solid's long-range order, defining microstructure.
• The selection of crystalline structure is complex, influenced by thermodynamics and kinetics.
• An intermediate region, termed 'pre-crystallization layer,' exists between liquid and solid states.

Purpose of the Study:

• Investigate the origin and properties of the pre-crystallization layer.
• Understand its role in the crystallization process and microstructure formation.
• Analyze the influence of solidification front orientation on this layer.

Main Methods:

• Atomistic simulation using classical molecular dynamics.
• Modeling of a Fe-Ni-Cr alloy system.
• Analysis of structural peculiarities and defect formation.

Main Results:

• The pre-crystallization layer exhibits distinct properties compared to both liquid and solid states.
• Structural features of this layer dictate primary defect formation in the solidified material.
• The layer's characteristics are dependent on the solidification front's orientation relative to the crystal lattice.

Conclusions:

• The pre-crystallization layer is a critical intermediary in melt crystallization.
• Its properties directly influence the primary microstructure and defect population.
• Controlling solidification front orientation can potentially tailor material properties via this layer.