The study focused to explore the effect of graphene (rGO) (0.3 wt.%) inside the yttria-stabilised zirconia (YSZ) matrix in terms of mechanical and functional properties. The samples were developed through the powder metallurgy route. The requisite amounts of powders were uniaxially pressed in disc shapes having 20 mm diameter and sintered at 1350 °C for half an hour in HT furnace. The sintered samples were thoroughly polished till the average surface roughness reached to 0.5 micron. The microstructure analysis revealed that the presence of graphene acts as a grain refiner result in homogeneous structure of grain morphology throughout the structure. Additionally, the presence of graphene significantly improved fracture toughness by 21% without compromise in hardness. The improvement was attributed to the refinement in gain morphology accompanied by crack bridging or deflection. The functional analysis revealed that the co-efficient of friction for 0.3 wt.% rGO inside YSZ improved by 20% compared to simple YSZ. A thin film formation (transfer film) developed between the interacting materials is responsible for the improvement in the co-efficient of friction. Hence, the developed ceramics that have excellent fracture toughness and tribological properties may suitably applied for production of ceramic seals.

Keywords: Graphene (rGO), Yttria Stabilized Zirconia (YSZ), Hardness, Fracture toughness, Coefficient of friction.