Effect of heat treatment on microstructure and mechanical property of Al–10%Mg2Si alloy

• After heat treatment, eutectic Mg2Si transforms to short fiber-like and spherical morphologies.
• A great number of nano-sized β″ particles (<20 nm) are embedded in the Al matrix.
• The evolution of microstructure gives rise to enhanced hardness and high tensile strength.

After solution treatment at 520 °C for 6 h and subsequent aging at 200 °C for 6 h, eutectic Mg2Si phase in Al–10%Mg2Si alloy transforms from long rod to short fiber-like and spherical morphologies, and a great number of nano-sized β″ particles precipitate in the Al matrix. The fine eutectic Mg2Si phase combined with nano-sized precipitates gives rise to enhanced hardness and high tensile strength of Al–10%Mg2Si alloy (increasing from 186 MPa to 234.6 MPa).