电磁搅拌对半固态Al-24%Si合金凝固过程及组织的影响  

Effect of Electromagnetic Stirring on Solidifying Process and Structure of Semi-solid Al-24%Si Alloy

作　　者：曹志强[1] 任振国[1] 张婷[1] 陈东风[1] 

机构地区：[1]大连理工大学铸造工程研究中心,辽宁大连116024

出　　处：《铸造》2005年第10期967-970,共4页Foundry

基　　金：国家自然科学基金资助项目(No.50274018)。

摘　　要：研究了Al-24%Si过共晶合金在未搅拌和电磁搅拌下凝固时,熔体沿径向的温度变化,以及凝固后组织变化,并用电子探针对基体的硅含量进行了定量测量。结果表明,施加搅拌时,合金温度沿半径方向仍然是从型壁到中心依次升高,但合金的径向温度梯度与未施加搅拌时相比大幅度减小;凝固后合金的共晶基体上产生了近球形或条状α相,且共晶基体的硅含量明显增大;降温速率低于10℃/min时,初生硅成簇状分散在合金的基体上,当降温速率增加到60℃/min时,初生硅成点状均匀分布在合金的基体上。During the solidifying process of the melt of Al-24wt%Si hypereutectic alloy, the variation of solidification structure and radial temperature with electromagnetic stirring and without stirring were investigated, and the Si content in the eutectic matrix was detected through electron microprobe. The results indicated although the temperature still was higher in the center than in the wall of mold, but the temperature gradient was significantly reduced; the spheroidal or rod a phases were found on the matrix of alloy and the Si content in the eutectic matrix was higher than that of non stirred casting. It is also found that the primary silicon particles were distributed in cluster on section of specimens when the cooling rate was less than 10 ℃/min, this phenomenon could be changed when the cooling rate was more than 60 ℃/min, in which primary silicon particles were distributed with dots on the macrostructure.

关 键 词：电磁搅拌 Al—24%Si合金 初生硅 组织 

分 类 号：TG249.9[金属学及工艺—铸造]