Investigation of metal matrix composite materials production by centrfugal casting

In this study, production of SiC particle reinforced aluminum matrixcomposites by centrifugal casting has been investigated. For this purpose,Etial 171 Al-Si alloys put in the SiC crucible was melted by means of amelting furnace. Liquid alloy was stirred by a stainless steel impeller coatedwith fireclay. Preheated SiC particles were added into the formed vortex toobtain 5, 10, 15, 20 vol % SiC reinforced aluminum based MMCs. Afterthe composite mixture was allowed to reach to 750 oC and was stirred for20 sec, it was poured by die casting and centrifugal casting. Both mouldswere hated up to 250 oC and their inner parts were coated with talc toavoid the castings adherence to the moulds. Microstructural andmechanical properties of these composites were investigated.Experimental evaluations showed that it could not be obtained desiredproperties for centrifugal casting composites, while die casting compositesgive satisfactory results. SiC particles distributed around inner part of crosssection of the cylindrical composites, whereas their distributions areexpected around outer part. Furthermore, centrifugal casting compositeshave higher porosity and this negatively affects the mechanical properties.Their hardness increase, but their ultimate tensile strength decrease withincreasing SiCp content in both die casting composite and centrifugalcasting composite.Key Words: Metal Matrix Composite, Vortex, Centrifugal Casting