Simulation of the cell to plane front transition during directional solidification at high velocity

Using the alloy phase-field method with a frozen temperature approximation, interface morphology and solute segregation patterns during directional solidification are examined near the high velocity (absolute stability) condition for planar growth. The dynamics of the breakdown of initially planar interfaces into cellular structures are shown. At sufficiently high solidification speed, a planar interface is reestablished after breakdown during the initial transient. The cell spacings, depths, tip temperatures, tip radii, and concentration patterns are determined as a function of solidification velocity. The presence of solute trapping is manifest in the variation of the degree of solute partitioning across the interfacial region with interface speed. Published by Elsevier Science B.V.