The hypoeutectic Al-6.34Mg-3.66Si is mainly used in the light-weight materials

however

the coarse Chinese script Mg

2

Si phase will seriously fracture the Al Matrix.Therefore

the effect of melt superheating temperature and time on the microstructure and mechanical properties of hypoeutectic Al-6.34Mg-3.66Si was investigated.The results show that with the superheat temperature at 850 ℃ for 25 min

the primary-Al phase is changed from fishbone-like dendrite to fine equiaxed crystal

and the thick lamellar Mg

2

Si is completely changed into fine fibrous with uniform distribution.The size of Mg

2

Si is decreased from 3.02μm to 0.97μm

which is 67.9% smaller than that of the original alloy.The tensile strength is increased by 34.4%

and the fracture mode is converted from the original brittle fracture to the combined one

presenting good plasticity.