A graphitic serpentine channel pouring process was used to prepare the semi-solid hypereutectic Al-Si alloy slurry and to refine the primary Si phase in the alloy.Effects of different Si content and pouring temperature on the size and morphology of primary Si phase in hypereutectic Al-Si alloy were investigated.The results show that the primary Si phase can be refined significantly via the serpentine channel pouring process.The varied pouring temperatures from 15 ℃ to 45 ℃ above the liquildus were investigated.The results reveal the smaller and more homogeneous primary Si phase can be obtained with decreasing pouring temperature.The primary Si phase can be well refined with the low Si content.It is difficult to break primary Si phase with increasing melt viscosity

so the size of primary Si phase is increased with increasing in Si content.