There are various modern processes usually employed in the production of castings vis-a-vis; sand-mould, permanent-mould, die and centrifugal castings. Sand-mould process is known to induce peculiar microstructures depending on average grain size, grain size distribution, grain shape and chemical composition. These affect specific properties such as surface finish, permeability and refractoriness.
In this study, the effect of using CO2 process, permanent mould, cement- bonded sand mould and natural sand mould on the hardness, tensile strength, impact strength and microstructure of cast 6063 Aluminum alloy is examined. The results show that there is significant increase in hardness (33.7BH) and strength (131.23Mpa) of the alloy when natural sand mould is used for its production.
Superior impact strength is exhibited in the alloy when permanent mould is used.
Keywords: aluminum, casting, mould, mechanical properties, microstructure