The effect of cooling rate on the microstructure and mechanical properties of Al-Si Alloy

A B ST R A C T This study focuses on a manufacturing process modification that can be carried out during the process of casting Aluminium-Silicon alloy in order to obtain desired properties and characteristics of a material for a particular usage. The effect of cooling rate was studied using sand and die moulds. Three types of mould were used namely dry sand mould, green sand mould and die mould .The result shows that the rate of cooling is faster in the die mould and the specimen obtained has the highest value of yield strength, ultimate tensile strength and hardness value but a low impact strength. The microstructure reveals that specimen A(dry sand mould) has a coarse microstructure, specimen B(green sand mould)exhibits a fairly wide spread distribution of silicon deposits while specimen C(die mould) exhibits fine and even distribution pf silicon deposits.