不同电磁场作用下Al-Sn合金的凝固组织

Effects of Different Electromagnetic Field on Microstructure of Al-Sn Alloy

Al-Sn合金由于具有大熔点差和宽结晶温度区间,易出现合金化不充分和晶粒充分生长形成粗大枝晶组织,造成比较严重的偏析。在凝固过程中施加不同电磁场和改变电流大小以获得组织均匀的Al-Sn合金。结果表明,施加电磁场后,Al-Sn合金晶粒明显细化,且行波磁场与复合磁场细化效果更加明显。Al-Sn合金中第二相偏析现象减轻,且随着电流强度增加,第二相分布更加均匀;通过对行波磁场(RMF)、旋转磁场(TMF)、复合磁场(RMF+TMF)处理后Al-Sn合金中的第二相分布比较,发现施加旋转磁场时,部分富Sn相有偏聚现象;而在行波磁场与复合磁场作用下,富Sn相没有明显的偏聚。

Due to the large difference of melting point and wide range of crystallization temperature,the alloying of Al-Sn alloy was prone to be insufficient and the coarse dendritic structure with serious segregation was also formed easily,and different type and current intensity of electromagnetic field was applied to obtain Al-Sn alloy with uniform microstructure.The results show that electromagnetic field has a great effect on the grain refinement,and with the enhancement of electromagnetic intensity,the grain will be finer.The segregation of second phase in Al-Sn alloy is weakened,and with the increase of the current intensity,the distribution of second phase becomes more uniform.By comparing the second phase of RMF、TMF、RMF+TMF treated Al-Sn alloy,it can be concluded that the tin-rich phase is segregated with RMF,and there is absence of segregation of tin-rich phase with the TMF and TMF+RMF treatment.