钪、锆变质处理和脉冲磁场对Al-3Fe合金凝固组织及硬度的影响

Effects of Sc,Zr Modification and Pulse Magnetic Field on Solidified Structure and Hardness of Al-3Fe Alloy

以高纯铝和Al-10Fe中间合金为原料制备Al-3Fe合金,在熔炼过程中加入质量分数分别为0.3%和0.1%的钪和锆元素对熔体进行变质处理,在凝固过程施加不同电压(100,200,300 V)、不同频率(2.5,5,10 Hz)的脉冲磁场,研究了变质处理和脉冲磁场对Al-3Fe合金凝固组织和硬度的影响。结果表明:钪、锆变质处理,脉冲磁场(100 V,5 Hz)及二者复合处理均可以有效细化合金的凝固组织,其中复合处理的细化效果最好,Al_(3)Fe相由未处理时粗大的长针状变为细小的短棒状或短针状。复合处理条件下,随着脉冲电压的增加,Al_(3)Fe相长度先增加后减小;随着脉冲频率的增加,Al_(3)Fe相长度减小。变质+脉冲磁场复合处理后,合金的布氏硬度提高最明显。

Al-3Fe alloy was prepared with high-purity aluminum and Al-10Fe master alloy as raw materials. In the melting process, 0.3 wt% Sc and 0.1 wt% Zr were added to modify the melt. During the solidification process, pulsed magnetic field with different voltages(100, 200, 300 V) and frequencies(2.5, 5, 10 Hz) were applied. Effects of modification and pulsed magnetic field on the solidified structure and hardness of Al-3Fe alloy were studied. The results show that Sc and Zr modification, applying pulsed magnetic field(100 V, 5 Hz) and their combination could refine solidified structure of the alloy effectively, and the composite treatment had the best refinement effect;Al_(3)Fe phase changed from coarse long needle under untreatment conditions to fine short rod or short needle. Under composite treatment, the length of Al_(3)Fe phase increased first and then decreased with the increase of pulse voltage, and decreased with the increase of pulse frequency. After modification and pulsed magnetic field composite treatment, Brinell hardness of the alloy increased the most.