Fabrication and characterization of SiC-reinforced Al-4032 metal matrix composites

Aluminium metal matrix composites (AMCs) have become quite popular for light weight, low cost, and good workability. The present work reports the impact of silicon carbide (SiC) reinforcement on the physical, microstructural, and mechanical characteristics of Al-4032/SiC composites with 4, 6, 8% of SiC (particle size 54 mu m) fabricated through bottom pouring stir casting set-up. Density and porosity measurements of the AMC samples have been performed using the rule of mixture. The microstructure of the AMC samples has been analyzed using optical microscope (OM), x-ray diffraction analysis (XRD), and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). The mechanical properties, in terms of the ultimate tensile strength (UTS), elongation, micro-hardness, and impact toughness of the AMCs have also been measured according to American society for testing and materials (ASTM) standards. A maximum 1.52% increase in theoretical density, while a maximum 2.92% decrease in experimental density has been recorded for 8% reinforcement. The UTS, microhardness, and impact toughness of the AMC samples have been found to improve significantly owing to the addition of ceramic particles. The uniform distribution of SiC particles all over base Al-4032 matrix material has been noticed by SEM and OM for AMCs up to 6% reinforcement. The reinforcement particles tend to agglomerate beyond this composition.