中文摘要：

研究直流脉冲磁场和孕育处理共同作用对纯铝凝固组织的影响,探讨直流脉冲磁场和孕育处理的共同作用的细化行为.结果表明：直流脉冲磁场能够显著细化纯铝凝固组织.纯铝的细化主要是由直流脉冲产生的电磁过冷和强制对流引起的.然而只在直流脉冲作用下,等轴晶区域的晶粒尺寸分布不均匀.在施加直流脉冲磁场的基础上加入质量分数为0.05％的Al-5Ti-B,晶粒尺寸更加细小,并且整个等轴晶区域的晶粒尺寸分布比较均匀;随着输出电流的增加,平均晶粒尺寸减小,当脉冲电源的输出电流增加到100A时,平均晶粒尺寸减小到113 μm.

英文摘要：

The combined effects of direct current pulsed magnetic field （DC-PMF） and inoculation on pure aluminum were investigated, the grain refinement behavior of DC-PMF and inoculation was discussed. The experimental results indicate that the solidification micro structure of pure aluminum can be greatly refined under DC-PMF. Refinement of pure aluminum is attributed to electromagnetic undercooling and forced convection caused by DC-PMF. With single DC-PMF, the grain size in the equiaxed zone is uneven. However, under DC-PMF, by adding 0.05% （mass fraction） Al5Ti-B, the grain size of the sample is smaller, and the size distribution is more uniform than that of single DC-PMF. Furthermore, under the combination of DC-PMF and inoculation, with the increase of output current, the grain size is further reduced. When the output current increases to 100 A, the average grain size can decrease to 113 μn.