Separation mechanism of the primary Si phase from the hypereutectic Al-Si alloy using a rotating magnetic field during solidification
Separation mechanism of the primary Si phase from the hypereutectic Al-Si alloy using a rotating magnetic field during solidification
复制标题
凝固过程中利用旋转磁场从过共晶铝硅合金中分离初生硅相的机理
DOI：
10.1016/j.actamat.2014.03.031
复制
发表时间：
2014-06-15
期刊：
影响因子：
9.4
通讯作者：
Li, T. J.
中科院分区：
文献类型：
--
作者：
Jie, J. C.;Zou, Q. C.;Li, T. J.
了解强流场下合金的凝固行为对于控制工业中合金的微观和宏观组织具有重要意义。研究表明，在过共晶Al-Si合金凝固过程中，采用旋转磁场（RMF）能有效地使初生Si相向坩埚内壁聚集，形成65-698 wt.%的富Si层Si含量。铝硅合金熔体在旋转磁场下的流动和液态金属的温度场是初生硅相偏析的两个主要条件。强烈的熔体流动，二次流和Taylor-Gortler涡流的作用，携带含硅量较高的液相，促使靠近坩埚内壁低温处形成的初晶Si相长大，最终导致初晶Si相的显著偏析。研究结果表明，强熔体流动与适当的冷却条件相结合，可以显著改变合金的凝固组织，有利于组织控制。(C)2014 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Understanding solidification behavior under an intense flow field is important in controlling the microstructure and macrostructure of alloys in industry. In the present study, we show that using a rotating magnetic field (RMF) during solidification of hypereutectic Al-Si alloy can efficiently congregate the primary Si phase to the inner wall of the crucible and form a Si-rich layer with 65-698 wt.% Si content. The Al-Si melt flow under an RMF and the temperature field of the liquid metal are the two dominant conditions for the segregation of the primary Si phase. The intense melt flow, i.e., secondary flow and Taylor-Gortler vortices, carries the bulk liquid with higher Si content to promote the growth of the primary Si phase formed close to the inner wall of the crucible where the temperature is low, finally resulting in the remarkable segregation of the primary Si phase. This work has demonstrated that a forced intense melt flow combined with proper cooling conditions can greatly change the solidification structure of alloys, which is beneficial to microstructure control. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.