Comparison of Microstructure and Mechanical Properties of A356/SiC Metal Matrix Composites Produced by Two Different Melting Routes

A356/SiC metal matrix composites with different weight percent of SiC particles were fabricated by two different techniques such as mechanical stir casting and electromagnetic stir casting. The results of macrostructure, microstructure, and XRD study revealed uniform distribution, grain refinement, and low porosity in electromagnetic stir casing samples. The mechanical results showed that the addition of SiC particles led to the improvement in tensile strength, hardness, toughness, and fatigue life. It indicates that type of fabrication process and percentage of reinforcement are the effective factors influencing the mechanical properties. It is observed that when percentage of reinforcement increases in electromagnetic stir casting, best mechanical properties are obtained. 1. Introduction The main challenge in the development and processing of engineering materials is to control the microstructure, mechanical properties, and cost of the product. The aluminum metal matrix composite materials are the combination of two or more constituents in which one is matrix and other is reinforcement [1–3]. If the casting processes of the melted metal are applied directly in the state of melted Al matrix with reinforcement, the reinforced metal matrix composite parts with the complicated shape can be produced. However, it is hard to get the products for the reinforcement to be distributed uniformly because of the difference of densities of matrix and reinforcement in metal matrix composite [4–6]. The mechanical properties of MMCs are sensitive to the processing technique used to fabricate the materials. Considerable improvements may be achieved by applying science-based modeling techniques to optimize the processing procedure. Several techniques have been employed to prepare the composites including powder metallurgy, melt techniques, and squeeze casting [7–10]. Investigation of mechanical behavior of aluminum alloys reinforced by hard particles such as SiC is an interesting area of research. Therefore, the aim of the present work is to investigate the effects of different factors such as: (i) weight percentage of the SiC particles (ii) type of fabrication process (mechanical stir and electromagnetic stir casting) on the microstructure, mechanical properties and wear behavior of the metal matrix composites [11, 12]. On the basis of literature review, the compositions of reinforcement selected in a multiplication of 5 and the percentage of reinforcements are varied from 0 to 15% weight fraction in metal matrix. If the weight percentage of reinforcement’s increases