Research Progress on Primary Phase Refinement in Hypereutectic Al-Si Alloys

The research progress on the primary phase refinement in hypereutectic Al-Si alloys is reviewed from the aspects such as alloying, modification and casting. The influence of main alloying elements on the properties of hypereutectic Al-Si alloys is introduced and the refinement effect of modifiers is analyzed. Also the effects of casting process on the mechanical properties of the alloys are discussed. It is pointed out that the future research direction should be focused on the clarification of the refinement mechanism of the primary phase, adoption of the appropriate modifiers and optimization of the casting process.