远场来流作用下纯熔体液固平直界面的稳定性分析

Stability analysis of a planar liquid/solid interface of directional solidification in pure melt under perturbation of a far-field flow

摘要: 利用渐近分析方法研究在小的远场来流扰动作用下纯熔体内具有液固平直界面的凝固过程的稳定性,导出了液固界面的扰动振幅变化率与波数的色散关系,以此为基础给出了具有液固平直界面的凝固过程的稳定性判据,揭示了金属凝固过程中液固平直界面转变为胞晶界面的内在机理.

Abstract: The stability of a planar liquid/solid interface of solidification in pure melt under perturbation of a small far-field flow was studied by using asymptotic analysis. A dispersion relation between the wave number and perturbation amplification rate was derived, and the morphological stability of planar liquid-solid interface of solidification was determined. The results reveal the mechanism of the transition from planar interface to cellular interface in directional solidification.