磁场对Cu-Pb-La过偏晶合金液-液分离的作用

本实验在Cu-80%Pb过偏晶合金凝固过程中添加稀土元素La,研究不同冷却速度下稀土元素在过偏晶合金凝固制备中的作用,并研究施加磁场对Cu-Pb过偏晶合金液-液分离区凝固组织的影响,探讨了磁场下第二相的迁移和分布规律,为均质偏晶合金制备技术的改进提供参考。结果表明,添加La元素可显著降低Cu-80%Pb凝固组织中的宏观偏析,促进第二相颗粒的均匀分布和细化。较快的冷却速度下添加La元素的作用更加明显,偏析程度显著降低,在此冷速下进一步施加1 T水平方向磁场,Cu-Pb-La合金凝固过程中宏观偏析得到了抑制,富Cu相颗粒弥散,组织分布均匀。

Effect of Magnetic Field on Liquid-liquid Separation

La element was used in the solidification process of Cu-80%Pb hypermonotectic alloy, and its effect under different cooling rates was discussed. The effect of magnetic field on microstructure of Cu-Pb hypermonotectic alloy in liquid-liquid separation region was studied, and the mechanism of transition and distribution of second phase was discussed. The results show that the addition of La element significantly decrease the macrosegregation in the solidification structure of Cu-80wt%Pb alloy, and promote the homogeneous size distribution and the size refinement of the second phase. The effect of La under a relatively fast cooling rate is more apparent to reduce segregation, and the further imposition of 1 T magnetic field inhibits the macrosegregation in solidified Cu-Pb-La alloys, leading to a homogeneous distribution of dispersed Cu-rich particles.