研究了在稳恒强磁场和低强度工频交变电流复合作用下产生的电磁振荡对Al-6wt%Si合金初生相尺寸分布的影响规律.结果表明:电流密度一定时,随磁场强度增大初生α-Al逐渐向颗粒状组织转变;磁场强度一定且小于4T时,随着电流密度的增加,初生α-Al相的尺寸缓慢增大,分布在大尺寸区段范围内的比例逐步增加;当磁场强度达到4T时,初生相α-Al的大小随电流密度的变化不明显,分布在各个尺寸区段范围内的比例基本上不变化.电磁振荡力的搅拌作用和空化效应是α-Al转变的主要机制.
The effect of simultaneous imposing high static magnetic field and alternating electric field on the solidification structure of Al-6 wt %Si alloy was investigated. The results showed that the form of primary α-Al changed from dendrite to granularity with the increasing of the intensity of high magnetic field at a certain current density. The size of primary α-Al increased gradually and the proportion of large size grains increased gradually with the increasing of the current density when the intensity of high magnetic field kept fix and was below 4T. The size of primary α-Al and the proportion remained unchanged with the increasing of the current density when the intensity of high magnetic field exceeded 4T. The mechanism of α-Al changing was due to the stirring of electromagnetic vibration and its cavitation effect.