中文摘要：

研究了Mn-89.8wt%Sb合金在无磁场以及磁场为B=8.8T、不同强度的磁场梯度作用下的凝固组织变化,并分析了上述不同强磁场条件对合金凝固组织影响的作用机理.研究表明,在较大梯度磁场作用时,试样中出现了初生MnSb相与Sb相以及共晶组织共存的现象,而且初生MnSb相与Sb相产生了明显的分层现象.此外,磁场梯度作用下初生MnSb相和Sb相的含量随着磁场梯度的增大而增加.论文对初生MnSb相和Sb相的分离机理进行了探讨,发现在梯度磁场作用下,熔融金属中不同磁化率的合金组元团簇受力不同,造成合金中合金组元团簇在熔融金属中定向移动,并呈梯度分布.当合金凝固时,形成Mn元素梯度分布的凝固组织.研究表明,利用梯度强磁场制备梯度功能复合材料是可能并且可行的.

英文摘要：

Mn-89.8wt% Sb alloys were solidified in the absence or presence of high magnetic fields of 8.8 T with various gradients to investigate the effects of high magnetic fields on the structures of the alloys. It was found that both of the two primary phases, i.e. MnSb and Sb appeared simultaneously in MnSb/Sb eutectic matrix and the MnSb and Sb phase-rich layers were aggregated in different domains under high gradient magnetic field conditions. It was also found that the volume fraction of these two primary phases increased with the increase of the field gradient. This process was attributed to that the alloying element clusters with different susceptibility in molten state were driven along or opposite to the direction of magnetic forces when subjected to high gradient magnetic fields and thus resulted in a layered microstructure with compositional gradient. The results of present study suggest that adjastment of high gradient magnetic field may potentially be used to tailor functionally graded materials.