The microstructure of cast Al-4Si-Mg reinforced with fly ash particles at various particle contents has been studied. The composites were fabricated by stir casting process and characterized by optical microscopy, image analyzer, scanning electron microscopy and hardness measurements. The results showed that particle contents affected to the presence of porosities and hardness of the composites. It was observed that increasing the fly ash content increase the porosity in the composites, with the matrix alloy reinforced with 15 wt.% of fly ash particles having the highest porosity and lowest hardness.

Keywords: Particle contents; Stir casting process; Hardness; Porosities

AJSTD Vol.23(1&2) pp.113-122 (2006)