Thermal effects in rapid directional solidification: linear theory

摘要: Abstract We study the morphological instability of planar solid/liquid interface for a unidirectionally-solidified dilute binary mixture. use model developed by Boettinger et al., Aziz, and Jackson which allows nonequilibrium effects on through velocity-dependent segregation attachment kinetics. Two types instabilities are found in linear stability analysis: (i) cellular instability, (ii) an oscillatory driven disequilibrium effects. Merchant Davis characterized these subject to frozen-temperature approximation (FTA). The present work relaxes FTA including latent heat full temperature distribution. Thermal slightly postpone onset but dramatically instability; however, absolute-stability conditions, at high speed suppressed, remain unchanged from FTA. critical wavenumber can be zero or nonzero depending material parameters. experimental observations banding correlated with predictions our theory.