中国物理B ›› 2018, Vol. 27 ›› Issue (11): 116402-116402.doi: 10.1088/1674-1056/27/11/116402

所属专题: SPECIAL TOPIC — 80th Anniversary of Northwestern Polytechnical University (NPU)

• SPECIAL TOPIC—Recent advances in thermoelectric materials and devices • 上一篇    下一篇

Metastable phase separation and rapid solidification of undercooled Co40Fe40Cu20 alloy

Xiaojun Bai(白晓军), Yaocen Wang(汪姚岑), Chongde Cao(曹崇德)   

  1. 1 Research and Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen 518057, China;
    2 Department of Applied Physics, Northwestern Polytechnical University, Xi'an 710072, China
  • 收稿日期:2018-07-05 修回日期:2018-09-07 出版日期:2018-11-05 发布日期:2018-11-05
  • 通讯作者: Yaocen Wang, Chongde Cao E-mail:Wangyc@nwpu.edu.cn;caocd@nwpu.edu.cn
  • 基金资助:

    Project supported by the National Key Research and Development Program of China (Grant No. 2016YFB1100101), the National Natural Science Foundation of China (Grant No. 51471135), Shenzhen Science and Technology Program, China (Grant No. JCYJ20170815162201821), Shaanxi Provincial Key R&D Program, China (Grant No. 2017KW-ZD-07), and the Fundamental Research Funds for the Central Universities, China (Grant No. 31020170QD102).

Metastable phase separation and rapid solidification of undercooled Co40Fe40Cu20 alloy

Xiaojun Bai(白晓军)1,2, Yaocen Wang(汪姚岑)1,2, Chongde Cao(曹崇德)1,2   

  1. 1 Research and Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen 518057, China;
    2 Department of Applied Physics, Northwestern Polytechnical University, Xi'an 710072, China
  • Received:2018-07-05 Revised:2018-09-07 Online:2018-11-05 Published:2018-11-05
  • Contact: Yaocen Wang, Chongde Cao E-mail:Wangyc@nwpu.edu.cn;caocd@nwpu.edu.cn
  • Supported by:

    Project supported by the National Key Research and Development Program of China (Grant No. 2016YFB1100101), the National Natural Science Foundation of China (Grant No. 51471135), Shenzhen Science and Technology Program, China (Grant No. JCYJ20170815162201821), Shaanxi Provincial Key R&D Program, China (Grant No. 2017KW-ZD-07), and the Fundamental Research Funds for the Central Universities, China (Grant No. 31020170QD102).

摘要:

The metastable liquid phase separation and rapid solidification behaviors of Co40Fe40Cu20 alloy were investigated by using differential thermal analysis (DTA) in combination with glass fluxing and electromagnetic levitation (EML) techniques. The critical liquid phase separation undercooling for this alloy was determined by DTA to be 174 K. Macrosegregation morphologies are formed in the bulk samples processed by both DTA and EML. It is revealed that undercooling level, cooling rate, convection, and surface tension difference between the two separated phases play a dominant role in the coalescence and segregation of the separated phases. The growth velocity of the (Fe,Co) dendrite has been measured as a function of undercooling up to 275 K. The temperature rise resulting from recalescence increases linearly with the increase of undercooling because of the enhancement of recalescence. The slope change of the recalescence temperature rise versus undercooling at the critical undercooling also implies the occurrence of liquid demixing.

关键词: undercooling, metastable phase separation, rapid solidification, immiscibility

Abstract:

The metastable liquid phase separation and rapid solidification behaviors of Co40Fe40Cu20 alloy were investigated by using differential thermal analysis (DTA) in combination with glass fluxing and electromagnetic levitation (EML) techniques. The critical liquid phase separation undercooling for this alloy was determined by DTA to be 174 K. Macrosegregation morphologies are formed in the bulk samples processed by both DTA and EML. It is revealed that undercooling level, cooling rate, convection, and surface tension difference between the two separated phases play a dominant role in the coalescence and segregation of the separated phases. The growth velocity of the (Fe,Co) dendrite has been measured as a function of undercooling up to 275 K. The temperature rise resulting from recalescence increases linearly with the increase of undercooling because of the enhancement of recalescence. The slope change of the recalescence temperature rise versus undercooling at the critical undercooling also implies the occurrence of liquid demixing.

Key words: undercooling, metastable phase separation, rapid solidification, immiscibility

中图分类号:  (Liquid-liquid transitions)

  • 64.70.Ja
64.70.D- (Solid-liquid transitions) 64.75.-g (Phase equilibria) 64.60.My (Metastable phases)