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 so lidification are examined near the high velocity (absolute stability) condi tion for planar growth. The dynamics of the breakdown of initially planar i nterfaces into cellular structures are shown. At sufficiently high solidifi cation speed, a planar interface is reestablished after breakdown during th e 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 interf ace speed. Published by Elsevier Science B.V.