Abstract:An analytical model was developed to describe Si-As alloy solidification in the whole range of measured interface velocity. It is demonstrated that at low interface velocity, the solidification occurs in the initial transient regime. The model leads to good comparison with the experimental data taking both local nonequilibrium effects at high interface velocity and steady state effects at low interface velocity into account. The local nonequilibrium diffusion effects shrink the initial transient period and lead to diffusionless solidification at high interface velocity.

Key words: alloy solidification; initial transient; local-nonequilibrium diffusion; hyperbolic diffusion equation; Si-As alloys; diffusionless solidification; complete solute trapping