Effect of Rapid Solidification and Addition of Cu3P on the Mechanical Properties of Hypereutectic Al-Si Alloys

The combined processes; rapid solidification, addition of Cu3P compound and heat treatments to improve the mechanical properties of the hypereutectic Al-13Si, Al-20Si and Al-20Si-1.5Fe-0.7Mn alloys (in wt. %) was studied. Optical microscopy and scanning electron microscopy were used to characterize the microstructures. The mechanical properties were evaluated by tensile tests. It was found that the cooling rate (20-50°C/s) used to solidify the alloys plus the addition of Cu3P compound favored the formation of fine primary Si and the transformation of the Al/Si eutectic from acicular to semi-t...