EFFECT OF MELT SUPERHEAT ON DIRECTIONAL SOLIDIFICATION PROPERTIES OF Al-Cu ALLOY

The effect of the melt superheat on the solute distribution coefficient and the critical condition of the interface morphology on the directional solidification has been studied. It is found that the actual distribution coefficient of solute is a function of liquid state. An increase of superheat of the melt causes the increase of actual distribution coefficient for such elements of K_0<1, and the decrease of the critical conditions of G/R associated with the stability of the solid-liquid interface morphologies which seems to be available to improving the directional solidification.