Study on the grain refinement of an Al-Zn-Mg-Cu alloy prepared by LFEC process
Low frequency electromagnetic casting(LFEC)process has been developed for years with the application of an induction coil outside the conventional direct chill(DC)casting mould.It has been demonstrated that the LFEC process has a significant grain refining effect on aluminium alloys.However,how it refines the microstructure is still not clearly understood.In the present work,the temperature measurement were carried out to study the temperature field during casting and to understand the mechanism of the grain refining effect of the LFEC process.The results showed that in contrast to the conventional DC casting process,during the LFEC process,the liquid melt flowing from the launder into the mould is cooled with very high cooling rate directly to 3-6 oC below the liquidus and the temperature field of the entire melt in the mould and the hot top is quite uniform,which results in enhanced heterogeneous nucleation and improved survival rate of the nuclei.This is believed to be the main reason why the LFEC process can significantly refine the grain size of aluminium alloys.
Al-Zn-Mg-Cu alloy grain refinement low frequency electromagnetic casting DC casting temperature measurement
ZUO Yu-bo ZHAO Zhi-hao ZHANG Hai-tao QIN Ke CUI Jian-zhong
Key Laboratory of Electromagnetic Processing of Materials,Ministry of Education,Northeastern University,Shenyang,110819,Liaoning,China
国际会议
The 7th International Conference on Electromagnetic Processing of Materials(第七届冶金与材料电磁过程国际大会)
北京
英文
1-5
2012-10-22(万方平台首次上网日期,不代表论文的发表时间)