Microstructure and Mechanical Properties of Hybrid Aluminum Composite with SiC Reinforcement

Abstract

Aluminum matrix composites (AMCs) are widely used in automotive and aerospace industries. The material exhibits better mechanical and physical properties such as high hardness, good wear resistance, and also lighter in weight compared to the aluminum alloys. Aluminum metal matrix composites (MMCs) can be produced by two ways, either in situ or ex situ techniques. Each technique has its own advantages and limitations, in terms of wettability, mechanical properties and others. The purpose of this study is to produce and characterize the microstructure and properties of the hybrid aluminum MMCs, which were produced by combining in situ process using magnesium silicide (Mg2Si) reinforcement and ex situ process using silicon carbide (SiC) reinforcement. The experiments have been conducted by varying weight fractions of SiC (0, 5, 10 and 15%). The hybrid MMCs were produced through stir casting due to its simplicity and less expensive technique. The reinforcements’ distribution and the fracture mode of the tensile samples were observed using the scanning electron microscope (SEM). Mechanical properties were measured using the Vicker’s hardness tester and the tensile machine. The results had shown that aluminum MMCs without SiC has the best properties compared to the other samples. This happens due to improper wettability of SiC inside the matrix, SiC clustering and high porosity level when weight fraction of SiC was increased.