Investigation of tribo-mechanical performance of nano-TiC/rGO based hybrid magnesium alloy-based metal matrix composites under dry sliding condition

Abstract

The current study systematically investigated the tribo-mechanical properties of magnesium-based hybrid nanocomposites. To fabricate magnesium alloy (AZ91) based composite by reinforcing nano-sized titanium carbide (nano-TiC), with weight percentages (wt.%) varying from 0.5% to 2% while maintaining a constant 0.5 wt.% of nano-reduced graphene oxide (rGO) throughout the experiments. The hybrid magnesium metal matrix nanocomposites (HMMMNCs) were prepared via the powder metallurgy procedure. The addition of hybrid reinforcements into the AZ91 matrix has a significant impact on its physical, mechanical, and tribological properties. The microhardness of the composite samples exhibited a significant enhancement, with an increase of ∼45.9% compared to the matrix material. This improvement in strength is attributed to the synergistic reinforcement effect of both nano-TiC and rGO. Additionally, at the optimal nano-TiC concentration of 1.5 wt.%, the wear rate and coefficient of friction (COF) of the HMMMNCs were decreased by ∼40.7% and ∼49.33%, respectively. This reduction is primarily due to the formation of a hardened ceramic phase in the contact region, which mitigates heat-induced softening. Also, different analytical tools, like XRD, SEM, and surface roughness profilometer, were employed to characterize the developed composite materials and analyze the worn surfaces.