强磁场对Al-Cu合金凝固组织及溶质分布的影响

对亚共晶Al-10.5%Cu(质量分数)合金进行了均恒强磁场和梯度强磁场下的凝固实验，考察了强磁场对凝固组织形貌及α-Al晶粒内溶质含量的影响.实验结果表明，施加均恒强磁场和梯度强磁场后，组织形貌变化不明显，而α-Al晶粒内溶质含量有所增加.分析认为，这是因为强磁场下的洛仑兹力抑制了凝固过程中固液界面处的Cu原子向液相内的迁移，从而提高了溶质元素在α-Al晶粒内的含量.改变梯度强磁场的方向，α-Al晶粒内溶质含量无明显变化.

Effects of High Magnetic Fields on Solidified Microstructure and Solute Element Distribution in Al-Cu Alloy

The solidification of Al-10.5wt%Cu hypoeutectic alloy was carried out in uniform and gradient high magnetic fields. The influences of high magnetic fields on the morphology of microstructure and solute elements content inside α-Al grains were investigated. The results revealed that the solute element content inside grains is increased by uniform high magnetic fields while the morphology of microstructure keeps almost unchanged. And, these phenomena are analyzed from the viewpoint of the Lorentz force which suppresses the migration of Cu atoms towards the liquid phase at the solid/liquid interface and consequently increases the solute element content inside α-Al grains. For gradient high magnetic fields, the solute content inside α-Al grains changes insignificantly when the direction of gradient high magnetic fields is changed.