Rapid colloidal solidifications under local nonequilibrium diffusion conditions

Partition coefficient for rapid solidification of colloidal suspensions has been calculated under local nonequilibrium diffusion conditions typically used when processing advanced materials. It has been demonstrated that the local nonequilibrium diffusion effects stabilize the planar solid liquid interface and lead to an abrupt transition to diffusionless solidification with complete particle trapping. The effective diffusion coefficient, which depends on interface velocity and particle size, has been introduced. It explains the strong dependences of the partition coefficient and the velocity leading to absolute stability of a planar solid–liquid interface on particle size.

► We model particle trapping in rapid colloidal solidification.
► The model predicts a sharp transition to diffusionless solidification.
► Complete particle trapping occurs at a finite interface velocity.
► Partition coefficient and interface stability depend on particle size.