摘要
采用在常规结晶器上布置线圈而开发的低频电磁半连续铸造技术(LFEC)制备2524铝合金扁铸锭并系统研究其对微观组织和宏观偏析的影响。结果表明,采用低频电磁半连续铸造技术制备的扁铸锭具有更加细小、均匀的铸态组织,而且组织由枝晶和蔷薇型转变为等轴晶组织。低频电磁半连续铸造技术对铸锭宏观偏析具有重要的影响,施加磁场后铸锭中心部分的反偏析明显减弱了。同时,对这些作用的机理进行了探讨。
Low frequency electromagnetic casting （LFEC） process with the application of an induction coil outside the conventional direct chill （DC） casting mould was used to prepare the flat ingot of 2524 alloy and the effect of electromagnetic field on the microstructure and macrosegregation of this alloy was systematically studied. The results show that the fiat ingot prepared by the LFEC process has a finer and more uniform as-cast microstructure and the grain morphology is transformed from dendrite and rosette-like to equiaxed structure. The LFEC process also shows a significant effect on macrosegregation, and with the application of electromagnetic field during casting process, the segregation in the centre of the ingot is obviously reduced. The mechanism of these effects was also discussed.
基金
Projects(51104043,51374067)supported by the National Natural Science Foundation of China
Project(2012CB619506)supported by the National Basic Research Program of China
Project(N120409002)supported by the Fundamental Research Funds for the Central Universities,China
关键词
2524铝合金
晶粒细化
凝固
微观组织
宏观偏析
低频电磁铸造
2524 aluminium alloy
grain refinement
solidification
microstructure
macrosegregation
low-frequencyelectromagnetic casting
