(哈尔滨理工大学 材料科学与工程学院，哈尔滨 150080)
摘 要: 利用自行研制的交替变向电磁场凝固装置， 采用对比实验方法研究了交替变向电磁场对Al-5%Cu合金晶粒度、 集中缩孔、 分散缩孔和缩松以及致密度的影响规律及机理。 结果表明： 交变电磁场对Al-5%Cu合金晶粒形貌和晶粒尺寸产生明显的影响； 随着磁场强度的增加， 合金晶粒形貌由粗大的柱状晶转变为细小的等轴晶，晶粒尺寸由30.2 mm降低到0.2 mm； 在0.2 T强场下试样集中缩孔相对深度缩小了10倍左右， 分散缩孔和缩松数量明显减少，铸件的致密度提高了2.9％。
关键字: Al-5％Cu合金; 交替电磁场; 集中缩孔; 缩松
in Al-5%Cu alloy
（ School of Materials Science and Engineering,
Harbin University of Science and Technology,Harbin 150080, China）
Abstract: Effects of alternating electromagnetic field on the grain size, concentrating shrinkage cavity, dispersing shrinkage porosity and density of Al-5%Cu alloy were investigated by comparative methods using self-made alternating electromagnetic field apparatus. The results show that the alternating electromagnetic field has a significant effect on the grain morphology and grain size of Al-5%Cu. The grain morphology is changed from a very big columnar structure to a fine equiaxed one and the grain size is decreased from 30.2 mm to 0.2 mm with the increase in alternating electromagnetic field intensity. The depth of concentrating shrinkage cavity is decreased about ten times when magnetic intensity is 0.2 T. The volumes of both dispersing shrinkage cavity and shrinkage porosity are reduced, leading to the increase in alloy density about 2.9%.
Key words: Al-5%Cu alloy; electromagnetic field; concentrating shrinkage cavity; shrinkage porosity
