低频电磁搅拌对半固态铝合金中稀土分布的影响  

EFFECTS OF ELECTROMAGNETIC STIRRING WITH LOW CURRENT FREQUENCY ON RE DISTRIBUTION IN SEMISOLID ALUMINUM ALLOY

作　　者：刘政[1] 刘小梅[1] 朱涛[1] 谌庆春[2] 

机构地区：[1]江西理工大学机电工程学院,赣州341000 [2]江西理工大学材料科学与工程学院,赣州341000

出　　处：《金属学报》2015年第3期272-280,共9页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目51361012;江西省自然科学基金项目20114bab206014;江西省教育厅科技项目GJJ14407资助~~

摘　　要：应用Maxwell 2D软件模拟了电磁结晶器中磁感应强度及其随电流频率的变化规律,研究了低频率电磁搅拌下A356-Y合金中RE在合金熔体中的分布规律以及对合金凝固组织的影响.结果表明,在工频以下的低频率段,通过数值模拟获得了磁感应强度较强的电流频率;在这个电流频率下,利用电磁搅拌制备了半固态A356-Y合金浆料,其中初生相的等积圆直径和形状因子分别达到65 mm以下和0.80以上,可满足半固态流变成形的要求;稀土Y在电磁场的驱动下,其分布沿着铸锭的半径趋于边缘富集,但受电流频率的影响;在所研究的范围内,随电流频率增大,稀土Y趋向铸锭边缘富集.When solidification of Al alloy melt was disturbed by electromagnetic field, its microstructure and properties were influenced by the diffusion and distribution of the solute and refinement in the melt. So it was necessary to study the metallurgical behavior of RE with electromagnetic stirring and to probe its diffusion and distribution under the forced convection in the melt. The magnetic induction intensity in the electromagnetic crystallizer and its variations with current frequency were simulated by Maxwell 2D software. The distribution of RE in the A356- Y alloy melt and its effect to the microstructure were studied with low frequency electromagnetic stirring.The results indicated that current frequency with stronger magnetic induction could be obtained during the range of low frequency under the working frequency. The slurry of semisolid A356-Y alloy was prepared by electromagnetic stirring at the frequency. The size and shape factor of the primary phase in the alloy were below 65 mm and above 0.80, respectively, which could satisfy the requirement of semisolid alloy rheoforming. The distribution of Y enriched at the edge of the ingot along its radius direction by the driving of electromagnetic field, but was effectedby the frequency. Y presented the enriching at the edge of the ingot with the increase of the frequency under the range of the frequency tested.

关 键 词：铝合金 电磁搅拌 电流频率 半固态 稀土 

分 类 号：TG146[一般工业技术—材料科学与工程] TG244[金属学及工艺—金属材料]