Effect of Chemical Composition of the Matrix on AlSi/SiC_p+C_p Composite Structure

The casting processes using mechanical stirring of composite suspension are considered for the most economical methods for manufacturing of metal matrix composites in the application and industrial practice. The most common problems during the composite suspensions production include: weak wetting between liquid Al alloy and ceramic particles and gassing of composite mixtures resulting with introducing the particles into aluminium alloy and long-term stirring process. The agglomerates and clusters of particles created among others as an effect of gas blisters absorption on the surface of ceramics causes discontinuity of composite structure and thereby they reduce properties of final products. The porosity has disadvantageous effect on mechanical properties of products, it reduces the corrosion and wear resistance, particularly under technically dry friction conditions. Therefore, to produced the casts composite possessed optimal properties, it is necessary their minimal porosity. To obtaining a good high-quality castings, the proper selection of components, particularly the chemical composition of the Al matrix and the kind of reinforcement are necessary. In this paper, the effect of chemical composition of the matrix on AlSi/SiC_p+C_p composite structure were presented.