The study on the influence of Si addition on the microstructure and hardness Al-Si alloys

Abstract

Alloys composed mostly of aluminum have been very important in aerospace manufacturing since the introduction of metal skinned aircraft. Silicon is good in metallic alloys used for casting. This is because it increases the fluidity of the melt, reduces the melting temperature, decreases the contraction associated with solidification and is very cheap as a raw material. Silicon also has a low density (2.34 g cm^-3), which may be an advantage in reducing the overall weight of the cast component. Silicon is hard and hence improves the abrasion resistance.

The aluminum silicon alloy is prepared by conventional die-casting method with approximately 7.5wt%,12.5wt% & 17.5wt% Si. In this study, the influence of silicon addition on the microstructure and hardness of Al–Si has been investigated. This project gives a comparison of microstructure property between hypoeutectic, eutectic and hyper eutectic aluminum silicon alloy. The increase in silicon content results in an increase in the hardness of the Al-Si alloys.