The combined electromagnetic fields were achieved by the application of an alternating magnetic field and a stationary magnetic field and were used during direct chill(DC) casting process to control the microstructure and macrosegregation of an Al-Zn-Mg-Cu alloy. Ingot microstructures were analyzed under an optical microscope(Leica DMR). The composition at different locations in the ingots was measured with inductively coupled plasma mass spectrometry(ICP) method. The results showed that the grain structure is transformed from dendrite to equiaxed structure and significantly refined with the application of combined electromagnetic fields. The uniformity of microstructure is also greatly improved. The combined electromagnetic fields show a significant effect on the distribution of elements. The negative macrosegregation in the centre area of the ingot is obviously reduced.
Yu-bo ZuoXu-dong LiuChao SunSen-sen YuanDan MouZhan-zhi LiJian-zhong Cui
Aluminum has been the secondly main metallic material in the world, whose mechanical properties are very important for industrial applications. The sizes and shapes of grains are important in determining the performance in structural applications. How to control the microstructure during solidification process has been a research focus. This paper gives an overview on the recent progress in microstructure control for aluminium alloys solidification process, and introduces the different methods to control the microstructure in detail. The mechanisms of microstructure control for different methods are also discussed. Finally, a brief prospect on future work is presented.
WANG XiangJieLUO XiaoXiongCONG FuGuanCUI JianZhong
