定向共晶组织的熔化行为

应用定向凝固／重熔技术研究了Ａｌ－Ｃｕ，Ａｌ－Ｎｉ和Ａｌ－Ｓｉ合金定向生长共晶组织的熔化行为。实验结果表明：共晶组织的熔化过程与共凝固生长过程之间不存在完全的互道性。无论是规则片状或棒状共晶组织，或是不规则片状共晶组织，其熔化过程都是共晶组织的两相首先在熔化界面上同时分解，形成各自的分散相，然后这些成分不同的分散相经过进一步溶解混合才形成成分均匀的单一液相。

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/remeltingtechnique. No complete reversibility of processes between melting of eutectic structure and itssolidification was revealed. The melting processes of eutectic structures, not only regularlamellar or rodlet but also irregular lamellar, may be that the two component phases of aneutectic 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.