Strong magnetic field-induced segregation and alignment of nonmagnetic particles
Strong magnetic field-induced segregation and alignment of nonmagnetic particles
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DOI：
10.1063/1.3535270
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发表时间：
2011-03
影响因子：
3.2
通讯作者：
Zhi Sun;M. Guo;J. Vleugels;O. Biest;B. Blanpain
中科院分区：
文献类型：
--
作者：
Zhi Sun;M. Guo;J. Vleugels;O. Biest;B. Blanpain
强磁场，例如，>10 T，被认为是去除细小非金属夹杂物和制备相关各向异性材料过程中的重要工具。本文用含铝氧化铝颗粒的模型系统研究了强磁场效应。施加梯度磁场会引起相当大的偏析，而在重力场中由于对流而没有观察到偏析。高梯度磁场与颗粒尺寸和处理时间一起是产生偏析的重要因素。同时，在强磁场处理后检测到磁取向。发现氧化铝的（00l）晶面沿强磁场方向排列。实验结果与基于磁能理论的理论计算相吻合。此外，还估算了取向所需的旋转时间，发现15 μm氧化铝颗粒的取向所需时间小于1 μ m。
A strong magnetic field, e.g., >10 T, is considered an important tool in the process of small nonmetallic inclusions removal and related anisotropic materials preparation. In the present paper, a model system of aluminum containing alumina particles is used to investigate the strong magnetic field effects. Considerable segregation is induced by the applied gradient magnetic field, whereas no segregation is observed in a gravity field because of the convection. A high gradient magnetic field, together with the particle size and treatment time, is an important factor in generating the segregation. At the same time, magnetic alignment is detected after the strong magnetic field treatment. The (00l) crystal planes of alumina are found to be aligned to the strong magnetic field direction. Experimental results agree with the theoretical calculations based on the theory of magnetic energy. Additionally, the rotation time for the alignment is estimated and the time for alumina particles of 15 μm is found to be <1...