摘要

To explore the heterogeneous nucleation mechanism of Mg-Al alloy refined by Al4C3, the valence electron structure and cohesive energy of Al4C3 crystal were calculated using the empirical electron theory of solids and molecules. A novel model to account for heterogeneous nucleation process of alpha-Mg on Al4C3 is described. The weak bonds exist in the surface of Al4C3 might leads to the replacement of atoms in Al4C3 surface by Mg atoms in melt, which ultimately result in easily stacking of Mg atoms on the newly formed surface of Al4C3. This model also indicates that Mg-Al atom cluster preferentially occupies the atom vacancies on Al4C3 surface in comparison to Mg-Mg atom cluster, which can decrease the refining efficiency of Al4C3 in high Al containing magnesium alloys.

  • 出版日期2017-12
  • 单位辽宁工业大学