Development and Characterization of Aluminum Hybrid Metal Matrix Composites Used in Automotive Applications

Abstract

Aluminum matrix composites (AMCs) are widely used in high performance applications especially in the manufacture of automotive parts where the pressure to use light-weight material has been interest of sustainability issues. The material exhibits better mechanical and physical properties such as high hardness, good wear resistance, and also lower density compared to the aluminum alloys. Aluminum metal matrix composites (MMCs) can be produced by two approaches, either in-situ or ex-situ techniques. In the present study, by adding SiC particles into Al-Si-Mg melt, Mg2Si and SiC particles hybrid reinforced Al matrix composites were fabricated through in-situ process using magnesium silicide (Mg2Si) reinforcement and ex-situ process using silicon carbide (SiC) reinforcement The effects of SiC particle addition with varying weight fractions of SiC (0, 5, 10 and 15 wt%) on the microstructure and tensile properties of Mg2Si/Al composites were investigated by using scanning electron microscopy (SEM) and XRD and tensile test. The results show that, with addition of 5 wt% SiC particles to Al-Mg2Si composite the size of Mg2Si particles decreased drastically from 70 µm to 40 µm. Furthermore, with increasing the fraction of the SiC particles from 5 wt% to 10 wt%, the morphologies of the primary Mg2Si particles in the prepared samples remain polygonal, but the size of the primary phase decreases slightly. However, when the SiC particle addition reaches 15 wt%, the morphologies of the primary Mg2Si particulates change partially from polygonal to quadrangular with a decrease in size from 30 μm to 20 μm. The tensile properties of the Al-20Mg2Si composite increased as a result of the addition of the SiC particles. The Al/(Mg2Si + 10 wt% SiC) owns the highest UTS (77.45 MPa) and El (%) (0.6) compared to other hybrid composites due to less porosity level inside the sample and proper interfacial bonding in the interface of SiC and aluminum matrix. Fracture behavior of Al/(Mg2Si + 10 wt% SiC) hybrid composite showed broken SiC particles and acceptable cohesion between SiC and matrix.