Effect of intensive shearing on morphology of primary silicon and properties of hypereutectic Al–Si alloy

Abstract Al–17Si–0·01Sr alloy melt was intensively sheared in the liquid state using the melt conditioning by advanced shear technology (MCAST) process before high pressure die casting (HPDC). The resultant microstructure and mechanical properties were examined and compared with those of the same alloy produced by the conventional HPDC process. It was found that intensive melt shearing can result in fine and equiaxed primary silicon particles uniformly distributed in the aluminium matrix, giving rise to much improved ductility and wear resistance.