Acta Metallurgica Sinica (English Letters) ›› 2012, Vol. 25 ›› Issue (2): 160-168.DOI: 10.11890/1006-7191-122-160

• 研究论文 • 上一篇    

低频电磁铸造7075铝合金的微观组织及力学性能

王高松1,赵志浩2,崔建忠1,郭强1   

  1. 1. 东北大学材料电磁过程研究教育部重点实验室
    2. 东北大学材料电磁过程教育部重点实验室
  • 收稿日期:2011-04-14 修回日期:2011-06-30 出版日期:2012-04-25 发布日期:2012-04-11
  • 通讯作者: 王高松

Microstructure and mechanical properties of low frequency electromagnetic casting 7075 aluminum alloy

Gaosong WANG, Zhihao ZHAO, Jianzhong CUI, Qiang GUO   

  1. Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110819, China
  • Received:2011-04-14 Revised:2011-06-30 Online:2012-04-25 Published:2012-04-11
  • Contact: Gaosong WANG

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摘要： 通过力学性能、扫描电镜、X射线衍射物相分析及透射电镜，观察了合金微观组织，并研究热处理工艺对常规铸造及低频电磁铸造(LFEC)7075铝合金的力学性能的影响，确定低频电磁铸造铝合金最佳热处理工艺。结果表明：低频电磁铸锭较常规DC铸锭晶粒细小、分布均匀。低频电磁铸锭挤压棒的微观组织保持了其原始铸态组织晶粒细小的特点。在相同的挤压比条件下，LFEC挤压棒的平均晶粒直径约为10μm，而普通DC挤压棒的平均晶粒直径约为20μm。低频电磁铸造7075铝合金同样具有很强的时效特性，T6处理峰值时效制度为120℃/24h，LFEC挤压棒的抗拉强度、维氏硬度、电导率可达673.50Mpa、194.62、32.4%IACS，均优于常规挤压棒，且工艺制度适合于工业大规模生产。

Abstract: This work explores the microstructure of low frequency electromagnetic casting (LFEC) 7075 aluminum alloys and investigates the effect of heat treatment process on its mechanical properties $via$ the mechanical properties test, X-ray diffraction and transmission electron microscopy. It was found that the grains of LFEC ingot were finer and more evenly distributed than that of the conventional direct chill cast (DC) ingots. The microstructure of LFEC ingot extruded kept their original as-cast structure with small and fine grains. With the same extrusion ratio, the average grain diameters of LFEC and conventional DC extruded were about 10 and 20 µm, respectively. LFEC extruded also had a better aging property, since the regime of T6 treatment peak value aging was at 120 ℃ for 24 h, the tensile strength and hardness (HV) of the LFEC extruded were 673.50 MPa and 194.62, respectively, which were all higher than those of the conventional DC extruded, indicating that the process regime can be applied in the industrial production.

Key words: LFEC, Aging, 7075 aluminum alloy, Microstructure, Property

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