Response to artificial ageing of dendritic and globular Al–7Si–Mg alloys

The age hardening capacity of dendritic and globular Al–7Si–Mg alloys was investigated. The morphology of the α-Al matrix has no effect on the age hardening capacity of Al–7Si–Mg alloys while Mg content does. The precipitation sequence of Al–7Si–Mg alloys with more than 0.3 wt.% Mg is the same as that of excess-Si Al–Mg–Si alloys. These alloys offer a significant age hardening capacity unlike Al–7Si–Mg alloys with less than 0.3 wt.% Mg which decompose predominantly with Si precipitation.