ABSTRACT
Contrary to the isothermal freezing of a pure metal, a liquid alloy freezes partially and gradually until its temperature drops to an eutectic temperature and then the remaining liquid freezes isothermally at that temperature (the solidus temperature). Thus, there is a “mushy” region between the solid and the liquid and the three regions are separated from each other by two isothermal surfaces, one at the solidus and the other at the liquidus temperatures. This chapter discusses the formulation of a three-phase free boundary problem arising in alloy solidification. It also studies the problem with heat flux prescribed on the fixed boundary.
