电场对A1-4%Si亚共晶合金凝固组织的影响

Effect of Electric Field on Microstructure of Al-4%Si Hypoeutectic Alloy

研究了不同电流密度下直流电场、交流电场对A1-4%Si亚共晶合金凝固组织的影响。结果表明,直流电场、交流电场都使合金初生相α-Al枝晶间距和晶粒大小产生变化,直流电场下随着电流密度的增加枝晶间距和晶粒逐渐减小,在电流密度达到最大值32.5mA/mm2时,枝晶间距和晶粒最为细小;交流电场下随着电流密度的增加,α-Al枝晶间距和晶粒也经历了一次细化过程。枝晶间距和晶粒的细化使合金的力学性能提高。

Variation of the solidified structure of Al-10% S i hypoeutectic alloy under direct current （DC） and alternating current （AC） electric field were studied. The results show that both DC and AC electric field can affect the arm spacing of the dendrite and the grain size of the primary phase α -Al. When the current density increases under the DC electric field, the spacing of the dendrite and the grain size gradually reduced and achieved the finest as the current density reaches the maximum 32.5 mA/mm^2. Under the AC electric field, the arm spacing of the α-Al dendrite and the grain size are also refined with the increases of the current density, and achieved the finest when the current density reaches 19.5 mA/mm^2. The refinement of the arm spacing of the dendrite and the grain size improves the .mechanical property of the alloy.