Tribological Capabilities of Graphene and Titanium Dioxide Nano Additives in Solid and Liquid Base Lubricants

Jankhan Patel,Amirkianoosh Kiani

doi:10.3390/app9081629

Jankhan Patel, Amirkianoosh Kiani

Open Access

https://doi.org/10.3390/app9081629

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Journal: Applied Sciences	Publication Date: Apr 19, 2019
Citations: 13	License type: CC BY 4.0

Affiliation: University of Ontario Institute of Technology

Abstract

In this study, the tribological behavior of both liquid (oil) and semi-liquid (grease) lubricants enhanced by multilayer graphene nano platelets and titanium dioxide nano powder was evaluated using ball-on-disk and shaft-on-plate tribo-meters. Oil samples for both 2D graphene nano platelets (GNP) and titanium nanopowders (TiNP) were prepared at three concentrations of 0.01 %w/w, 0.05 %w/w and 0.1 %w/w. In addition, 0.05% w/w mixtures of GNP and TiNP were prepared with three different ratios to analyze collective effects of both nano additives on friction and wear properties. For semi-liquid lubricants, 0.5% w/w concentrations were prepared for both nano additives for shaft-on-plate tests. Viscosity and oxidation stability tests were conducted on the liquid-base lubricants. Nano powders of both additive and substrate were analyzed using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). In addition, Raman spectroscopy was conducted to characterize the graphene and titanium dioxide. The study shows that adding graphene and titanium dioxide individually sacrifices either the wear or friction of lubricants. However, use of both additives together can enhance friction resistance and wear preventive properties of a liquid lubricant significantly. For a semi-liquid lubricant, the use of both additives together and individually reduces friction compared to base grease.

Highlights

Increasing demand for resources gives us an opportunity to concentrate on sustainable development, and this is not possible without considering all the aspects associated with a system.For automobile and mechanical industries where mating surfaces are used to transfer maximum energy, it is important to reduce both wear and friction, which results in less energy consumption and longer functional life for moving mechanical components in machinery [1]
Results show positive effects on base lubricants. Both nano additives showed no negative effect on oxidation life and viscosity; both additives reveal modifications in friction and wear properties
graphene nano platelets (GNP) demonstrate a great control over friction at 0.05% w/w

Summary

Introduction

For automobile and mechanical industries where mating surfaces are used to transfer maximum energy, it is important to reduce both wear and friction, which results in less energy consumption and longer functional life for moving mechanical components in machinery [1]. This can be achieved by making surfaces frictionless or by developing better lubricants that do not just control friction and wear but reduce clotting, oxidation, foaming, and corrosion problems in hydraulic systems [2]. A higher diffusion rate allows lubricants to reduce micro friction, which leads to reduced wear and heat concentration in machining processes [11]

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