过共晶Al-Si合金的电磁搅拌工艺研究  

Electromagnetic Stirring Process for Hypereutectic Al-Si Alloys

作　　者：李润霞[1,2] 陈玉金[2] 许传恒[2] 袁晓光[2] 李荣德[2] 

机构地区：[1]东北大学材料与冶金学院,辽宁沈阳110004 [2]沈阳工业大学材料科学与工程学院,辽宁沈阳110870

出　　处：《铸造》2010年第6期558-562,共5页Foundry

基　　金：国家自然科学基金(50971092);辽宁省创新团队项目(2007T132)支持

摘　　要：对过共晶Al-Si合金进行电磁搅拌后,针状或多边形状初晶Si变得细小,圆整,且分布均匀,针状及条状第二相发生断裂,长度减小,形状圆整而细小,分布也趋于均匀,合金的力学性能也有很大提高。对于过共晶Al-17.5Si合金,搅拌电压为50V的时候,搅拌效果最佳,合金力学性能最好。随着搅拌电压的继续升高,在交变磁场中的磁场力更强,Al-Si合金组织中初生Si和第二相组织团聚,晶粒变得粗大,力学性能反而下降。随搅拌时间的延长,Al-Si合金组织中初晶Si和第二相逐渐细化、圆整化,电磁搅拌效果越来越明显。但搅拌时间过长,对组织影响不大,反而因为裹入气体而导致力学性能下降。最佳搅拌时间为60s,合金组织相对细小,硬度达到最高。Effect of electromagnetic stirring on the hyper eutectic AI-Si alloy was studied. The results indicate that after the electromagnetic stirring, acicular or multilateral shape Si becomes tiny, circle, and distributes evenly; acicular and strip second phases break, the distribution also tends to be even. At the same time, the mechanical properties of alloy also improved. When the stirring voltage is 50 V, the stirring effect and the alloy mechanical properties are the best for the hyper-eutectic Al-17.5Si alloy. Along with stirring voltage enhancement and much stronger magnetic field strength, the primary Si and second phases agglomerated, and the mechanical properties decreased. With stirring time extension, primary Si and second phases gradually become tiny and circular; the electromagnetic stirring effect becomes more and more obvious. But when the stirring time is excessively long, the mechanical properties decrease because of the entrapped gas, so the optimal stirring time is 60 s.

关 键 词：过共晶Al—Si合金 电磁搅拌 显微组织 力学性能 

分 类 号：TG292[金属学及工艺—铸造]