| Aging behavior of Al-Mg-Si alloys with high silicon content was investigated in the present study. Excess silicon leads to unique aging behavior. The Al-Mg-Si alloys show seven exothermic peaks in DSC thermogram. These peaks seem to be induced by the formation of clustering of Si and Mg atoms, G-P zone, unknown small precipitates, β$quot; phase, B` phase, Si particle and β phase. The content of excess Si has no relationship with the precipitation of β$quot; phase and B` phase, but it affected on the formation of Si particles. Natural aging has a distinct influence on the subsequent precipitation process. It is proposed that the formation of stable silicon clusters during natural aging is the major reason for such an effect. |
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