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•A novel synthesis of FCS/GNP hybrid has been reported.•The formation of hybrid was confirmed using SEM, TEM and Raman spectroscopy.•The tribological performance of the hybrid was ...investigated using a four ball tester.•An 18% reduction in coefficient of friction was obtained for the FCS/GNP hybrid-2 (10:1) in neat oil.
A novel synthesis method of Functionalized Carbon Spheres (FCS) coated with Graphene nanoplatelets (GNP) using a simple sonication technique is reported. The FCS/GNP hybrid nanoparticles were found to be effectively improving the tribological characteristics of lubricating oils. For the synthesis of FCS, Carbon Spheres (CS) synthesized via non-catalytic chemical vapor deposition was functionalized using nitric acid. The hybrid nanoparticles were characterized using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Raman spectroscopy. The tribological behavior of CASTROL-20 W 40 engine oil dispersed with different concentrations of FCS and GNP using ultrasonication was investigated using a four-ball tester. The tribological behavior of FCS and GNP were investigated separately to compare the tribological performance of the FCS/GNP hybrid nanoparticles. The neat oil dispersed with 0.275 wt% of FCS/GNP hybrid nanoparticles in 10:1 ratio shows excellent dispersion and stability for 30 days without the addition of any surfactant. The results indicate that the addition of these hybrid nanoparticles causes a remarkable reduction (~18%) in the Coefficient of Friction (COF) of the neat oil. The optical image of wear scar on the ball immersed in neat oil shows a significant reduction in the Wear Scar Diameter from 425.6 µm to 390.0 µm with the addition of hybrid nanoparticles. The Raman mapping of the wear scar on chromium steel ball reveals that the FCS/GNP hybrid nanoparticles remain unseparated after the tribology test.
Nanoparticle technology has a significant impact on the development of lubricants. However, there is a need to understand the influence of various parameters of base oil and nanomaterials ...individually as well as in combination. To understand the influence of base oil on lubrication properties of magnetic lubricant, identical nanoparticle material (magnetite nanoparticles-MNP) dispersed in two different base oils: synthetic oil and mineral oil having the same order of viscosities. The MNP concentration varied from 0 to 10 wt% in both oils and the lubrication properties studied using four ball tester. For synthetic oil, the minimum Coefficient of Friction (reduced by 45%) and Wear Scar Diameter (by 30%) obtained at 4 wt% of MNP compared to the base oil. In the case of mineral oil, COF decreased by 56% and WSD by 46% for 6 wt% of MNP. The surface characterization and lubrication mechanisms were studied using various microscopy techniques. The results explained using the difference in molecular structure as well as nanoparticle stability in both oils.
•Nanolubricants are in the limelight in lubrication industries.•Carrier (Base oil) plays a vital role in the tribological properties of Nanolubricant.•Anti-wear and Anti-friction properties of magnetic nanofluids enrich by 56% and 46% compared by mineral oil, respectively.•The result shows the lubrication properties influence by the carrier and carrier-surfactant compatibility.•Aggregation in the magnetic nanofluid helps to improved tribological properties.
The demand for alternative fuels has risen in recent years due to the economic and environmental consequences of conventional fuels. In addition to engine characteristics, i.e., performance, ...combustion, and emission the lubricity of the considered fuel is an important parameter for its selection. This experimental study shows the tribological performance of the tire pyrolysis oil by using the four-ball tester. Waste tire pyrolysis oil was purified by using the distillation process. The experiment was conducted over 300 s at 40, 50, 63, and 80 kg load, 1800 rpm constant speed, and 27 °C temperature of all fuels on the ASTM D2266 standard. The tribological performance of the tire pyrolysis oil was compared with the BT10 (biodiesel 90%–tire pyrolysis oil 10%) and BT20 (biodiesel 80%–tire pyrolysis oil 20%) and biodiesel. The optical microscope is used to measure the wear scar diameter and then it is examined through a scanning electron microscope. In terms of greater load-carrying capacity, tire pyrolysis oil shows better anti-wear behaviour compared to biodiesel fuel. The wear scar diameter of BT10, BT20, and tire pyrolysis oil was 23.99%, 8.37%, and 32.62%, respectively, lower than the biodiesel fuel at 80 kg load. The SEM micrographs revealed that tire pyrolysis oil and BT10 displayed lower wear as compared to counterparts. Finally, it is concluded that BT10 is the most suitable fuel in terms of tribological performance.
Nanostructures as an inert additive to the lubricant act as a tiny friction reduction element by providing asperity filling, polishing, and film formation mechanism at the nanoscale dimension under ...the boundary layer regime. Here, we explore the synthesis and tribology application of iron‐carbon‐based nanoparticles encapsulated multiwall carbon nanotubes (Fe‐C‐CNTs). Three Fe‐C nanoparticles phase that is, Fe3C‐CNTs, Fe3C‐Fe‐CNTs, and Fe‐CNTs are synthesised. In particular, the emphasis here is on the effect of nanoparticle phase variation on the tribology property. The tribology property of the prepared nanomaterials is studied by dispersing it in commercially used Servo gearbox oil. The coefficient of friction and wear is found reduced in all dispersions compared to the base gearbox oil confirming the manifestation of nanoscale mechanisms at the tribo‐interface. It is revealed that the phase variation shows more impact on the alteration of friction coefficient compared to the dispersion concentration variation analysed using ANOVA two‐way technique. Further, the diameter and composition analysis of the wear scar is used to comprehend the underlying mechanism of the encapsulated particle phase variation. The findings suggest that the Fe‐CNTs dispersions are efficient in reducing friction to a larger extent but also promote the interface oxidation leading to enhanced wear and roughness whereas, Fe3C‐CNTs and Fe3C‐Fe‐CNTs are chemically stable providing smooth sliding and less wear.
The consciousness of deteriorating fossil fuels and the adverse impact of its consumption on human health have diverted the research towards alternate energy sources. Biodiesel seems to be the best ...promising alternate fuel for diesel engines as it has potential to partially or completely eliminate diesel from compression ignition (CI) engine. Several investigations on performance and emissions had shown that use of double biofuels (biodiesel-oil blends) have ability to completely replace diesel. But, the lubricating properties of fuel also affect the performance of engine as some engine parts are lubricated by the fuel itself. In the present study, effects of concentration of biodiesel in blend, temperature and load on friction and wear are investigated with the help of four ball tester. As biodiesel is subjected to oxidation and has highly affected lubricity at higher temperature and load, so the effect of oxidation was also studied. The operating loads and temperatures were 147–392N and 45–60–75°C respectively. During operation of four ball wear monitor, frictional torque was recorded with the help of data acquisition system. The scars on the balls are investigated with the help of microscope. An analytical ferrography was also done to analyze the wear debris in the used oil after each test. It was found out from the present investigation that the operating parameters collectively affect the lubricity.
Purpose
This paper aims to present an analysis of several 3 D texture parameters for the entire wear scars obtained in severe regime, on a four-ball tester. The aim of this analysis is to correlate ...the tribological parameter as wear scar diameter to texture parameters.
Design/methodology/approach
Tested lubricants were rapeseed oil, rapeseed oil additivated with 1% Wt nano TiO2 and rapeseed oil additivated with 1%Wt nano ZnO. The severe regime was applied for 1400 rpm and for loads increasing in steps of 50 N, from 500 to 900 N. Several analyzed roughness parameters (height parameters and functional ones) could be related to the evolution of a wear parameter, the wear scar diameter. Comparing the values for neat rapeseed oil and additivated variants, the texture parameters allow for evaluating if the additives protect or not the worn surfaces.
Findings
Measurements pointed out two groups of roughness parameters: one that has an evolution depending on wear scar diameter (WSD) and load (Sa, St, functional parameters) and one including Ssk that has shown no dependence on load and WSD. Also, the functional parameters Spk and Svk follow in a similar manner the wear parameter, WSD, but Sk is the least dependent on load. For the highest load, amplitude parameters such as Sa and St are following the tendency of WSD. Each lubricant has its particular correlation between wear parameters and texture quality, expressed by the help of a set of roughness parameters.
Research limitations/implications
Such studies help tribologists to rank lubricants based on a combined analysis with wear parameters and texture parameters.
Practical implications
The results allow for evaluating new formulated lubricants.
Originality/value
The study on the quality on worn surfaces introduces the original idea of analyzing the entire wear scar surface (approximated by an ellipse with the axes as those experimentally measured) by the help of a set of 3 D roughness parameters.
This work deals with the tribological performance of karanja oil trimethylolpropane ester (KOTMPE) biolubricant base oil for its probable application as automotive lubricant. The biolubricant was ...synthesized by transesterification of karanja oil methyl ester with trimethylolpropane (TMP) under acid catalyst. The study was made with Ducom TR30L four-ball tester at 1200 rev min
−1
speed and 75 °C temperature over 60 min duration under normal loads of 15 kg and 40 kg as per ASTM D 4172-94 A and B standard test method. Principal results at two loads are given here:
Coefficient of friction
(
CoF
) 0.100 and 0.042,
wear scar diameter
(
WSD
) 0.30 mm and 0.44 mm,
flash temperature parameter
(
FTP
) 80.932 and 126.249, and
thermal energy
(
TE
) 0.054 J and 0.060 J, respectively. The study found that KOTMPE has lowest CoF than any vegetable oil, TMP ester or commercial lubricant. Similarly, the WSD was lowest among all the vegetable oil based lubricants and was at par with SAE 20W-50 and SAE 40 commercial lubricants. FTP was better compared to any vegetable oil or TMP ester. Finally, the energy efficiency of KOTMPE was better than that of other vegetable oils, TMP esters and mineral lubricants. The synthesized ester demonstrated the outstanding performance in terms of friction and wear characteristics along with high thermal stability and energy efficiency worthy of comparison with multiple lubricating products reported by different research groups in available literature during last two decades.
•The COF of diesel is higher than biodiesel blends under various load condition.•The average WSD of diesel is 38.5% higher than other biodiesel blends.•PB20 contains lower amount of metal ...compositions under high load condition.•PB20 exhibits lower worn scar surface than diesel and other biodiesel blends.•PB20 has better lubrication properties than diesel and other biodiesel blends.
When an automobile engine is running it produces more friction and wear between the sliding components and lubrication is required for reducing the frictional effect. Friction and wear reduce engine life, reliability and increase the maintenance cost. This study investigated and compared the friction and wear characteristics of diesel, Calophyllum inophyllum, palm biodiesel, and their blends, by using the four-ball tester. The experimental test was conducted at 30°C, 45°C, 60°C and 75°C, under 40kg and 80kg loads, at a constant speed of 1800rpm for all samples. The average coefficient of friction of diesel was 28.8% and 23.4% higher than pure C. inophyllum and palm biodiesel respectively. The wear scar diameter of diesel was higher than biodiesel and biodiesel blends at different temperatures and loads. The highest amount of elements were found from CIB100 (45ppm), which changes by about 14.6ppm compared to ordinary oil. PB10 and PB20 have lower amounts of metal composition and oxide formation. PB20 exhibits a lower worn scar surface area than diesel and biodiesel blends. PB20 shows good lubrication performance and the possibility to form highly lubricating film without breaking down over a long time.
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