(1. 西安交通大学 理学院 材料物理系，西安 710049;
2. 西北工业大学 物理系， 西安 710072)
摘 要: 采用熔融玻璃深过冷技术和金相分析法，对Cu-(10%～30%)Co合金液态深过冷条件下的二次液相分解和合金的凝固行为进行了分析。研究表明，由于液相分解后富Co液相的溶解度随温度下降而降低，使Cu原子不断从富Co液相中分解出来。如果分解出的Cu原子不能扩散到富Cu液相中，会在富Co液相内形成富Cu液滴。但合金凝固后富Co相中富Cu相并非都来自于二次液相分解，一部分是来自于富Co液相长大和富Co相选分结晶。冷却曲线的测定结果和分析显示，Cu-Co合金液相分解后，富Co液相的结晶温度与合金成分和实验条件有关。富Co液滴结晶完成后发生了包晶转变。
关键字: 深过冷； 液相分解； 凝固； 金相组织； Cu-Co合金
Cu-Co alloys under deep supercooling
（1. Department of Physical Materials, School of Science,
Xi′an Jiaotong University， Xi′an 710049, P.R.China;
2. Department of Physics, Northwest Polytechnic University,
Xi′an 710072, P.R.China）
Abstract:The secondary liquid separation and solidification behaviors of Cu-(10%～30%)Co alloys under deep supercooling were investigated by means of fluxing glass deepsupercooling technology and metallographic analysis. The results reveal that Cuis continuously separated from Co-rich liquid as temperature decreasing. If Cu atoms can not diffuse into Cu-rich liquid phase, new Cu-rich liquid drops will form. Not all of Cu-rich phases in Co-rich matrix come from the secondaryliquid separation, one originates select solidifying and another result from Corich clusters growing. The cooling curves of alloys reveal that the crystallizing temperature of Co-rich phase is different with the variations of thecomposition and experiment condition. Peritectic reaction will occur after solidification of Co-rich liquid drops.
Key words: deep supercooling; liquid separation; solidification; microstructure; Cu-Co alloys
