期刊
ACTA MATERIALIA
卷 60, 期 8, 页码 3321-3332出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.actamat.2012.02.019
关键词
Columnar-to-equiaxed transition (CET); Thermoelectric magnetic force; Strong magnetic field
资金
- Bl-inter [09_473220]
- National natural Science Foundation of China [51171106, 2011CB610404]
- Shanghai Phosphor Science Foundation of China [10QA1402500]
- Shanghai Institutions of Higher Learning
The effects of strong magnetic fields on the columnar-to-equiaxed transition (CET) have been investigated experimentally. Six alloys have been directionally solidified at low growth speeds (1-10 mu m s(-1)) under magnetic fields up to 10 T. Experimental results show that the application of a strong magnetic field causes a dendrite fragmentation and then the CET. The thermoelectric magnetic force acting on cells/dendrites and equiaxed grains in the mushy zone has been studied numerically. Numerical results reveal that the value of the thermoelectric magnetic force increases as the magnetic field intensity and the temperature gradient increase. A torque is created on cells/dendrites and equiaxed grains. This torque breaks cells/dendrites and drives the rotation of equiaxed grains. The rotation of equiaxed grains in the mushy zone will further destroy cells/dendrites. Thus, with the increase of the magnetic field intensity and the temperature gradient, the volume fraction of equiaxed grains in front of columnar dendrites increases. When the magnetic field intensity and the temperature gradient reach a critical value, the growth of columnar dendrites is blocked and the CET then occurs. The present work may initiate a new method of inducing the CET via an applied strong magnetic field during directional solidification. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据