The Effects of Mould Materials on the Mechanical Properties of Aluminium Casting

Abstract

Centrifugal casting is a manufacturing process used to form cylindrical components with a central axis of rotatio. In continuous casting process, molten metal flows into the continuous casting mould, cools by cold water, and pulls out after solidification. In this research work, the effects of mold materials on mechanical properties of aluminium were investigated. Mould materials were prepared from sand, metal, and plaster of paris (POP). A steel rod of about 25mm in diameter was used as pattern to cast aluminium in these three mould materials. Test pieces were machined from the casting produced by each of the three mould materials for tensile, hardness and impact tests, as well as microstructure. It was observed from the tests that aluminium cast by sand has the highest value of ductility at the expense of its hardness, while those castings by metal and POP moulds have appreciable increase in hardness values but lesser values of ductility. The question as to which of the mould materials is the best depends on the engineering application requirements; sand mould would be preferred where ductility is the major requirement, while metal and POP moulds might be preferred when hardness is the priority.