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论文类型：期刊论文

发表时间：2018-04-25

发表刊物：JOURNAL OF ALLOYS AND COMPOUNDS

收录刊物：SCIE、EI

卷号：742

页面范围：99-106

ISSN号：0925-8388

关键字：Metastable immiscible; Cu-Fe alloy; Cooling rate; Constitutional undercooling; Microstructure evolution

摘要：Undercooling greatly influences the resultant solidification microstructure of an alloy, especially for metastable immiscible Cu-Fe alloy. In the present paper, solidification microstructure evolution of metastable immiscible Cu80Fe20 alloy was studied under different cooling conditions. For the first time, it is found that the liquid-liquid phase separation in Cu-Fe alloy is triggered by constitutional undercooling ahead of the solid-liquid interface. When the cooling rate is about 50-100 K/s, the liquid-solid transformation primarily takes place, and the liquid-liquid phase separation only exists in a small region or the interdendritic region about several tens to hundreds of microns. The liquid-liquid phase separation is ascribed to the large constitutional undercooling according to the calculation and occurs behind the liquid-solid transformation, which is different than found in previous studies. However, only normal liquid-solid transformation occurs and the morphology of the Fe-rich phase remarkably changes from cellular to developed dendrites in a cooling rate range of 350-560 K/s. The results provide significant guidance for industrial preparation and a necessary consideration for the study of metastable immiscible Cu-Fe alloy. (C) 2018 Elsevier B.V. All rights reserved.