MELTING BEHAVIORS OF DIRECTIONALLY GROWN EUTECTIC STRUCTURES

The melting behaviors of directionally grown eutectic structures of Al-Cu, AL-Ni and Al-Si alloys have been investigated using directional solidification/remelting technique. No complete reversibility of processes between melting of eutectic structure and its solidification was revealed. The melting processes of eutectic structures, not only regular lamellar or rodlet but also irregular lamellar, may be that the two component phases of an eutectic structure are priorly decomposed on the melting interfaces simultaneously, and dis- persed into liquid region as their own phases, then these disperse phases of different composi- tions dissolved further to form a homogeneous single liquid phase at higher temperatures.