Abstract
Aluminium metal matrix composites exhibiting superior mechanical and tribological properties have gained immense interest in recent years. These comosites are finding broad applications in the fields of automotive, aerospace, military and marine. Graphene Nanoplatelets (GNPs), as reinforcement in composites, have become a prime focus because of its exceptional characteristic properties. In the present study, GNPs are dispersed into the aluminium alloy as reinforcements by using stir casting method. To ensure proper dispersion, sintered pellets of aluminium mixed with GNPs are added to the molten metal. The dispersion of the GNPs and the microstructural changes due to the addition of GNPs are observed using Scanning Electron Microscopy (SEM) and elemental mapping. Vickers hardness tester is used to measure hardness of these samples. To compare the tribological properties of Al/GNP composite as well as pure alumimum samples, pin-on-disc experiments are conducted for a specific combination of sliding speed and sliding distance at different loading conditions. The weight loss, wear rate and coefficient of friction are measured and favourable effects of GNPs on tribological properties of Al/GNP composite are discussed. In addition, the wear mechanism has been understood in detail by conducting microstructural studies of the worn surfaces using SEM and Energy Dispersive Spectroscopy. It is observed that the Vickers hardness of the composite increased to a maximum of 25% while coefficient of friction decreased to a minimum of 26% for Al/GNP composite.
Preparation of SiC based Aluminium metal matrix nano composites by high intensity ultrasonic cavitation process and evaluation of mechanical and tribological properties
