Effecfs of gravity on interdendritic fluid flow in large remelted ingots

Abstract

This paper presents analytic calculations of the interdendritic fluid-flow in mush zones whose width is small compared to their length, a situation which is caracteristic of large remelted ingots. The flow is found to consist of two main components. The first one is normal to the isotherms which feeds solidifi­cation shrinkage and the second one is parallel to the isotherms which is produced by gravity acting on desity differences in the interdendritic liquid. If the isotherms are not exactly parallel, then the gravity induced flow parallel to the isotherms induces a component normal to it. This companent may cause the freckles that occur in remelted ingots when melting conditions are changed.