Tribological characterization of hybrid aluminum composite under boundary lubricating sliding conditions

Abstract

Tribological behaviour of hybrid aluminium composite is studied under lubricated sliding conditions. The scope of this study is to determine the fundamental tribological properties of grapheme as secondary reinforcement and to evaluate its performance under boundary lubricating conditions. The hybrid aluminium composite is fabricated by rapid spark plasma sintered processing route. Variable concentration of Graphene Nano platelets (GNP) [0.5, 1, 2, 3, 4, 5 wt%] is added to the Al-Si-6 wt% Al2O3 composite. The lubricant used is PAO base oil and SAE20W50 Engine oil. The effect of the load and sliding distance is studied on the ball-on-disc tribometer. It is reported that COF remain stable with the increasing sliding distance (90 m–450 m) and decrease with the increasing load (10 N −40 N) and then attain a steady stable value after 40 N to 80 N load. The possibility behind the low friction and wear is the exceptional lubricating effect of the GNP particles layer which mixes with the lubricating oil. The GNP particle layer are the 2D Nano particles that form a low shear stress junction protective layer at the sliding interface, which cause easy shear because of weak Vander wall force drastically reduce friction and wear of the hybrid composite.