Chin. Phys. B ›› 2013, Vol. 22 ›› Issue (1): 18101-018101.doi: 10.1088/1674-1056/22/1/018101

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Settling velocity of equiaxed dendrites in a tube

周鹏, 王猛, 林鑫, 黄卫东   

  1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China
  • 收稿日期:2012-08-08 修回日期:2012-10-31 出版日期:2012-12-01 发布日期:2012-12-01
  • 基金资助:
    Project supported by the National Basic Research Program of China (Grant No. 2011CB10402), the National Natural Science Foundation of China (Grant Nos. 50901061 and 50971102), and the Foundation of State Key Laboratory of Solidification Processing, China (Grant Nos. 02-TZ-2008 and 36-TP-2009).

Settling velocity of equiaxed dendrites in a tube

Zhou Peng (周鹏), Wang Meng (王猛), Lin Xin (林鑫), Huang Wei-Dong (黄卫东)   

  1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China
  • Received:2012-08-08 Revised:2012-10-31 Online:2012-12-01 Published:2012-12-01
  • Contact: Wang Meng E-mail:wangmeng@nwpu.edu.cn
  • Supported by:
    Project supported by the National Basic Research Program of China (Grant No. 2011CB10402), the National Natural Science Foundation of China (Grant Nos. 50901061 and 50971102), and the Foundation of State Key Laboratory of Solidification Processing, China (Grant Nos. 02-TZ-2008 and 36-TP-2009).

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摘要： The settling velocity of equiaxed dendrites can cause macrosegregation and influence the structure of the equiaxed zone during the casting solidification process. So an understanding of the settling characteristics is needed to predict the structure and segregation in castings. The settling velocity of NH4Cl equiaxed dendrites of non-spherical geometry was studied experimentally in an NH4Cl-70wt.%H2O solution. A calculation formula was proposed to calculate the settling velocity of sediment equiaxed dendrites in a tube filling with saturated solution at a moderate Reynolds number region. The retardation effects of wall and morphology of the equiaxed dendrite on the settling velocity were taken into account in the development of the calculation formula, and the correction function B of drag coefficient with consideration of the retardation effects of wall and morphology of the equiaxed dendrite on the settling velocity of the equiaxed dendrite was calibrated according to the experimental results. A comparison showed that the formula has a good accordance with the experimental results.

关键词: equiaxed dendrite, settling velocity, morphology effect, wall effect

Abstract: The settling velocity of equiaxed dendrites can cause macrosegregation and influence the structure of the equiaxed zone during the casting solidification process. So an understanding of the settling characteristics is needed to predict the structure and segregation in castings. The settling velocity of NH4Cl equiaxed dendrites of non-spherical geometry was studied experimentally in an NH4Cl-70wt.%H2O solution. A calculation formula was proposed to calculate the settling velocity of sediment equiaxed dendrites in a tube filling with saturated solution at a moderate Reynolds number region. The retardation effects of wall and morphology of the equiaxed dendrite on the settling velocity were taken into account in the development of the calculation formula, and the correction function B of drag coefficient with consideration of the retardation effects of wall and morphology of the equiaxed dendrite on the settling velocity of the equiaxed dendrite was calibrated according to the experimental results. A comparison showed that the formula has a good accordance with the experimental results.

Key words: equiaxed dendrite, settling velocity, morphology effect, wall effect

中图分类号:  (Metals, semimetals, and alloys)

  • 81.05.Bx
47.50.Cd (Modeling) 47.57.ef (Sedimentation and migration)