中文摘要：

采用电磁悬浮法使Cu40Co30Cr30的合金熔体达到深过冷，发现深过冷条件下合金很容易发生亚稳液相分离，同时冷却速率显著影响着样品的微观组织。经悬浮冷却凝固的样品发生液相分离，富Cu相中出现富（Co，Cr）相枝晶，富（Co，Cr）相中形成二次析出的富Cu相。在电磁搅拌作用影响下，二次析出的富Cu相呈椭球状。在用纯铜快淬的条件下，凝固后的微观组织更加细化，样品为一相以球状均匀弥散在另一相中，并且在富Cu相中发生了多次析出的现象。XRD结果表明，在两种实验条件下均发现Cu相和CoCr相的存在，说明不同的冷却速率对相组成基本没有影响。与Cu-Co—Fe和Cu-Co—Ni比较，Cu-Co-Cr发生液相分离所需要的过冷度和冷却速率更小，进行得更为彻底。

英文摘要：

Phase separation in undercooled Cu40Co30Cr30 alloys was investigated using electromagnetm levitation （EML） in combination with rapid quenching, the solidification microstructure of the sample was related to the cooling rates. In the sample processed by EML, many （Co,Cr） rich dendrities appeared in Cu rich matrix,and many axiolitic Cu-rich spheres were precipitated from the （Co,Cr）-rich phase. The sample processed by rapid quenching show that one phase disperse in the other phase in form of spheres and the mierostructure is finer. Multiple precipitated pheno menon happened in Cu-rich matrix. The X-ray diffraction （XRD） patterns indicate that only （Cu） and CoCr phases are found in the samples processed by both two methods. Compared with previous work about Cu-Co-Fe and Cu Co-Ni, the phase separation in Cu-Co-Cr alloys is more sufficient with smaller undercooling and lower cooling rates.