(大连理工大学 材料与科学工程学院,大连 116023)
摘 要: 采用固液复合的方法制备3003/4004和5056/AZ91两种不同结合类型的双金属复层材料,使用光学显微镜和XRD等手段分析电磁搅拌对复层界面凝固组织的影响。结果表明:施加电磁搅拌可以明显改变两种复层材料界面的凝固组织,对于3003/4004复层铸锭,未经处理时,4004一侧界面附近的凝固组织为粗大的树枝晶;而经电磁搅拌处理后,其界面附近凝固组织为非树枝状;对于5056/AZ91复层铸锭,未经处理时,金属间化合物主要聚集在过渡层处,靠近5056铝合金一侧的为Mg2Al3,靠近AZ91镁合金一侧的为Mg17Al12;而施加电磁搅拌后,Lorentz力会引起AZ91熔体强迫流动,反复冲刷外层5056凝壳导致重熔,大量铝元素被卷入铸锭内部与未凝固的镁合金熔体混合,使得从界面到心部均为单一的Mg2Al3相。
关键字: 复层材料;电磁搅拌;镁合金
(Department of Materials Science and Engineering, Dalian University of Technology, Dalian 116023, China)
Abstract:The solid-liquid compound method was used to prepare 3003/4004 and 5056/AZ91 clad ingots. The optical microscope and XRD were used to analyze the effect of electromagnetic stirring on the modification of solidification structure. The results show that, with electromagnetic stirring, the interface morphology of solidification structure obviously changes. For 3003/4004 clad ingot, without electromagnetic stirring, the solidification structure of 4004 aluminum alloy near the interface is coarse dendrite, when electromagnetic stirring is used, the solidification structure of 4004 aluminum alloy changes into non-dendrite crystal. For 5056/AZ91 clad ingot, without electromagnetic stirring, the of intermetallic compounds congregate on the interface, which closing to 5056 side and AZ91 side are Mg2Al3 and Mg17Al12. When electromagnetic stirring is used, the forced convection in AZ91 melt caused by Lorentz force washes against 5056 solidification shell to remelting, a great quantity of Al element involves in the core of the ingot and mixed with magnesium alloy melt, so that Mg2Al3 is generated from the interface to the core.
Key words: cladding materials; electromagnetic stirring; magnesium alloy


