Macro-segregation is a type of unacceptable defects, which normally occurs for aluminum alloys and other nonferrous alloys. In this work, the macro-segregation susceptibility (MAS) of some commercial 5000 and 6000 series alloys and some Al-Mg and Al-Mg-Si alloys are investigated via a criterion based on the solidification curves from thermodynamic calculations. Equilibrium solute distribution coefficients, k, with different initial alloying concentrations and their relationships with the MAS are discussed. Of all commercial 5000 and 6000 series aluminum alloys investigated, AA5754, AA5182, AA6181A and AA6016 have shown less susceptible to macro-segregation than others. Of all Al-Mg and Al-Mg-Si alloys investigated, Al-Mg alloys with higher Mg, Al-Mg-Si alloys with both higher Mg and Si have shown less susceptible to macro-segregation than other compositions. Finally, the role of mass transfer behavior in improving macro-segregation is discussed from the perspective of thermodynamic and kinetic calculations.

宏观偏析是一类不可接受的缺陷，通常发生在铝合金和其他有色合金中。在这项工作中，基于热力学计算中的凝固曲线，根据准则对某些商用5000系列和6000系列合金以及某些Al-Mg和Al-Mg-Si合金的宏观偏析磁化率（MAS）进行了研究。平衡溶质分布系数，k，讨论了具有不同初始合金浓度及其与MAS的关系。在所研究的所有商用5000和6000系列铝合金中，AA5754，AA5182，AA6181A和AA6016表现出比其他铝合金更不容易发生宏观偏析的现象。在所有研究的Al-Mg和Al-Mg-Si合金中，具有较高Mg的Al-Mg合金，具有较高Mg和Si的Al-Mg-Si合金比其他成分具有更小的宏观偏析敏感性。最后，从热力学和动力学计算的角度讨论了传质行为在改善宏观偏析中的作用。