Effect of transverse static magnetic field on radial microstructure of hypereutectic aluminum alloy during directional solidification  

作　　者：Shaodong Hu Long Hou Kang Wang Zhongmiao Liao Wen Zhu Aihua Yi Wenfang Li Yves Fautrelle Xi Li 

机构地区：[1]School of Materials Science and Engineering,Dongguan University of Technology,Dongguan 523808,China [2]State Key Laboratory Advanced Special Steel,Shanghai University,Shanghai 200072,China [3]School of Materials Science and Engineering,Xi'an Jiaotong University,Xi'an,710049,China [4]SIMAP-EPM-Madylam/G-INP/CNRS.PHELMA.38402 St Martin d'Heres Cedex.France

出　　处：《Journal of Materials Science & Technology》2021年第17期207-214,共8页材料科学技术（英文版）

基　　金：the National Natural Science Foundation of China(Nos.51571056,51690164 and 51904183);the Technological Innovation Projects of Universities in Guangdong Province(Nos.2017KTSCX177 and 2020KQNCX084);China Postdoctoral Science Foundation(No.2020M683463);Guangdong Basic and Applied Basic Research Foundation(No.2019A1515110135);the Natural Science Foundation of Guangdong Province(No.2018A030310024)。

摘　　要：The effect of different scales thermoelectric magnetic convection(TEMC)on the radial solidification microstructure of hypereutectic Al alloy has been investigated under transverse static magnetic field during directional solidification,focusing on the formation of freckle.Our experimental and numerical simulation results indicate that the TEMC circulation at sample scale under transverse static magnetic field leads to the enrichment of solute Al on one side of the sample.The TEMC and the solute enrichment degree increase with the increase of magnetic field when the magnetic field increases to 0.5 T.The enrichment degree of solute elements under magnetic field is affected by temperature gradient and growth rate.The non-uniform distribution of solute Al in the radial direction of the sample results in the non-uniform distribution of primary dendrite arm spacing(PDAS).Moreover,the applied magnetic field can lead to freckle formation and its number increases with the increase of magnetic field.The change of freckle is consistent with the anisotropy TEMC caused by the anisotropy of primary dendrite or primary dendrite network under magnetic field.Finally,the mechanism of synergism effect of the anisotropy TEMC,the distribution of solute Al and the PDAS on freckle formation and evolution is studied during directional solidification under magnetic field.

关 键 词：Static magnetic field Directional solidification Melt flow Radial solidification microstructure FRECKLE 

分 类 号：TG146.21[一般工业技术—材料科学与工程]