关键词: Al-Si母合金, Al-Si合金生产, 熔盐电解, 铝电解, 还原, 电沉积

Abstract: Al-Si alloys were produced by molten salt electrolysis using the molten cryolite-alumina system as electrolyte with SiO2 added in it. The morphology and chemical composition of such products were analyzed by SEM. The results indicated that the Si-content in alloys could be over 30% and therefore the products were hypereutectic Al-Si alloys. The morphological observation showed that the crystalline Si was typically of acicular structure. The hypereutectic Al-Si alloys can be used as Al-Si master alloy. Based on the experimental results, the mechanism of the process of preparing Al-Si master alloys was discussed. The reasons why the Al-Si master alloys form are considered as: 1) SiO2 is reduced by Al and 2) Si and Al are precipitated simultaneously on cathode. So keeping up the concentrations of A12O3 and SiO2 can make the electrolysis last all through. As a new approach to producing Al-Si master alloy, the preparation proposed is applicable to practical production.