(1. 西安交通大學(xué) 理學(xué)院 材料物理系，西安 710049;
2. 西北工業(yè)大學(xué) 物理系， 西安 710072)
摘 要: 采用熔融玻璃深過(guò)冷技術(shù)和金相分析法，對(duì)Cu-(10%～30%)Co合金液態(tài)深過(guò)冷條件下的二次液相分解和合金的凝固行為進(jìn)行了分析。研究表明，由于液相分解后富Co液相的溶解度隨溫度下降而降低，使Cu原子不斷從富Co液相中分解出來(lái)。如果分解出的Cu原子不能擴(kuò)散到富Cu液相中，會(huì)在富Co液相內(nèi)形成富Cu液滴。但合金凝固后富Co相中富Cu相并非都來(lái)自于二次液相分解，一部分是來(lái)自于富Co液相長(zhǎng)大和富Co相選分結(jié)晶。冷卻曲線的測(cè)定結(jié)果和分析顯示，Cu-Co合金液相分解后，富Co液相的結(jié)晶溫度與合金成分和實(shí)驗(yàn)條件有關(guān)。富Co液滴結(jié)晶完成后發(fā)生了包晶轉(zhuǎn)變。
關(guān)鍵字: 深過(guò)冷； 液相分解； 凝固； 金相組織； Cu-Co合金
Cu-Co alloys under deep supercooling
YANG Sen１， CAO Chong-de２, WEI Bing-bo２
（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
