Kinetic Solute Trapping Models for Silicon Anode Active Material Atomization
Kinetic solute trapping in rapid atomization suppresses coarse silicon crystallites by overriding equilibrium partitioning above critical interface speeds.
Aziz Model
Meaning
Mathematical formulations describing non-equilibrium solute partitioning at moving solid-liquid interfaces predict chemical composition during rapid solidification processes. Within alloy processing and laser additive manufacturing, the aziz model establishes the functional relationship between interface velocity and the non-equilibrium distribution coefficient. The formulation stops applying when interface speeds drop into the local equilibrium regime or exceed the absolute stability limit of crystal growth.
Solute Partitioning
Non-equilibrium conditions cause solute atoms to become trapped within the advancing crystal lattice at speeds exceeding diffusive relaxation rates. When interface velocity increases, the effective distribution coefficient approaches unity, suppressing elemental segregation during rapid cooling. This mechanism allows concentrations of secondary elements to exceed equilibrium solubility limits without forming coarse intermetallic phases.
Alloy producers use this behavior to generate supersaturated solid solutions that exhibit enhanced mechanical strength and refined microstructures after thermal treatment.
Kinetic Boundary
Diffusional velocity parameters set the transition threshold between equilibrium partitioning and complete solute trapping. Below this threshold, chemical species redistribute across the interface according to equilibrium phase diagrams. Above this threshold, solute atoms lack sufficient time to diffuse away from the advancing interface, forcing incorporation into the solid matrix regardless of thermodynamic preference.
Solidification Regime
Rapid thermal processing techniques rely on precise control of interfacial movement to engineer metastable microstructures. Atomization and laser melting exploit high interface velocities to form refined grains with uniform elemental distribution. At extremely high growth rates, crystal growth mode shifts from diffusive control to kinetic attachment, altering phase stability and mechanical response in the solid alloy.