Production and characterization of composite Al-15%Si produced by the Centrifugal casting method

One of the methods in production of composite materials with different chemical composition is the centrifugal casting method. In this research the centrifugal casting method has been used for making the alloy of Al-15%Si. With this method، reduction in volume of silicon particles on the surface zone of the samples is 25%. As a consequence the alloy hardness is increased and this alloy becomes applicable to resistance in suitable wearing. In this direction obtained results in wearing tests characterized that the formation of silicon particles in the distance of 20 mm from the surface causes the increase in the hardness of samples in the rate of 95 HV and consequently the increase to resistance in the wearing in these zones. In addition this microhardness shows one reduction almost linear with respect to the increase of distance from the surface. Also the studies on the wearing surfaces with the use of electronic microscope shows that the wearing surfaces containing of silicon particles separated and also the tribologic layers are attached together. These two cases both indicate the resistance to wearing of the produced samples by this method.