An Electromagnetic Compounding Technique for Counteracting the Thermoelectric Magnetic Effect During Directional Solidification Under a Transverse Static Magnetic Field
An Electromagnetic Compounding Technique for Counteracting the Thermoelectric Magnetic Effect During Directional Solidification Under a Transverse Static Magnetic Field
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DOI：
10.1007/s11661-018-4732-y
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发表时间：
2018-06
期刊：
影响因子：
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通讯作者：
Z. Shen;Bangfei Zhou;Y. Zhong;Licheng Dong;Huai Wang;L. Fan;T. Zheng;Chuanjun Li;W. Ren;W. Xuan;Z. Ren
中科院分区：
文献类型：
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作者：
Z. Shen;Bangfei Zhou;Y. Zhong;Licheng Dong;Huai Wang;L. Fan;T. Zheng;Chuanjun Li;W. Ren;W. Xuan;Z. Ren
在0.5T横向静磁场作用下，引入外加直流电以抵消Sn-10wt%Bi合金定向凝固过程中的热电磁效应。结果表明，随着外加直流电流密度的增加，热电磁效应引起的Bi的单侧偏聚逐渐减弱、消失，然后发生逆转。因此，提出了一种在磁场作用下抵消材料热电磁效应的新方法。为了验证该方法的正确性，分别测量和计算了Sn-10wt%Bi合金在实验条件下的绝对热电势和内部热电势电流。建立了二维数值模拟方法，模拟了在横向静磁场作用下，随着外加直流电流密度的增加，定向凝固过程中固液界面形貌、流场和成分偏析的演变。本研究不仅有助于了解强制流动对定向凝固组织和成分偏析的影响，而且为利用电磁复合技术消除偏析、获得更高质量的凝固组织提供了一种新的途径。
An external direct current (DC) was introduced to counteract the thermoelectric magnetic effect during the directional solidification of Sn-10 wt pct Bi alloy under a 0.5 T transverse static magnetic field. The results show that the single-side Bi segregation induced by the thermoelectric magnetic effect gradually becomes weakened, disappeared, and then reversed with the increasing current density of the external DC. Therefore, a new method for counteracting the thermoelectric magnetic effect during materials processing under the magnetic field was proposed. In order to verify this method, the absolute thermoelectric power of Sn-10 wt pct Bi alloy and the internal thermoelectric current under the experimental conditions were measured and calculated, respectively. A 2D numerical simulation was established to simulate the evolution of the solid–liquid interface morphology, flow field, and composition segregation with the increasing current density of the external DC during directional solidification under a transverse static magnetic field. The present study not only facilitates the understanding of the effects of the forced flows on the directionally solidified microstructures and composition segregation, but also provides a new way for eliminating segregation and obtaining the higher-quality solidification structure by using the electromagnetic compounding technique.