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

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; Al₃Fe phase changed from coarse long needle under untreatment conditions to fine short rod or short needle. Under composite treatment, the length of Al₃Fe 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.