AFM Investigation of Steels Surfaces Worn in HFRR Tests

2007 ◽  
Vol 537-538 ◽  
pp. 285-290 ◽  
Author(s):  
D. Aranyi ◽  
Péter M. Nagy ◽  
Zs. Oláh ◽  
Erika Kálmán
Keyword(s):  
Diesel Fuel ◽  
Steel Ball ◽  
Sulphur Content ◽  
Wear Scar ◽  
Wear Scar Diameter ◽  
Radical Reduction ◽  
Worn Surfaces

Radical reduction of sulphur content in diesel fuel from the mid 90’s had disastrous impact on diesel fuel’s lubricity. Due to the desulphurization process the lubricity of diesel fuel dropped significantly and got crucial nowadays. The lubricity performance of the diesel fuel is evaluated by the HFRR test in Europe. The HFRR value is determined by measuring the equivalent wear scar diameter occurred on the steel ball specimen during the test. The topographies of these wear scars were investigated by AFM and correlation between the morphology of the worn surfaces and the different HFRR values has been found.

scholarly journals Дослідження змащувальної здатності дизельного та авіаційного палива на паливному насосі високого тиску

2021 ◽  
Vol 2 (17) ◽  
pp. 26-30
Author(s):  
Стасис СЛАВИНСКАС ◽  
Томас МИЦКЯВИЧЮС ◽  
Арвидас ПАУЛЮКАС
Keyword(s):  
High Pressure ◽  
Diesel Fuel ◽  
Fuel Injection ◽  
Wear Scar ◽  
Aviation Fuel ◽  
Injection System ◽  
Test Bed ◽  
Wear Scar Diameter ◽  
Fuel Pump ◽  
Common Rail Injection System

This paper presents comparative experimental study’s results of diesel fuel and aviation fuel effect on operational properties of a high-pressure fuel pump of a common rail injection system. The two identical fuel injection systems mounted on a test bed of the fuel injection pumps were prepared for the experimental durability tests. The lubricity properties of diesel fuel and aviation fuel (Jet-A1) were studied using the High-Frequency Reciprocating Rig (HFRR) method. The values of wear scar diameter (WSD) obtained with Jet-A1 fuels were compared to the respective values measured with the reference diesel fuel. The microscopic photographs of the wear scar diameters obtained on above mentioned fuels are presented in the paper. The test results showed that long-term (about 300 hours) using aviation fuels produced a negative effect on the durability of the high-pressure fuel pump. Due to the wear of plunger-barrel units the decrease in the fuel delivery rate occurred of about 6.7 % operating with aviation fuel. The average friction coefficients of Jet-A1 fuels were higher than that of the normal diesel fuel. Keywords: diesel fuel, aviation Jet-A1 fuel, lubricity, plunger-barrel units, wear scar diameter

3D texture parameters for wear scars after severe regime

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lorena Deleanu ◽  
Traian Florian Ionescu ◽  
George Catalin Cristea ◽  
Cornel Camil Suciu ◽  
Constantin Georgescu
Keyword(s):  
Rapeseed Oil ◽  
Wear Scar ◽  
Roughness Parameters ◽  
Wear Scar Diameter ◽  
Content Type ◽  
Functional Parameters ◽  
3D Texture ◽  
Texture Parameters ◽  
Practical Implications ◽  
Worn Surfaces

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.

Frictional Performance of an Ionic Liquid/Graphene Composite Additive in Lubricating Oil

NANO ◽  
2021 ◽  
pp. 2150111
Author(s):  
Shengli You ◽  
Ming Zhou ◽  
Mingyue Wang ◽  
Xin Chen ◽  
Long Jin ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Friction Pair ◽  
Testing Machine ◽  
Steel Ball ◽  
Wear Scar ◽  
Wear Testing ◽  
Lubricating Oil ◽  
Wear Scar Diameter ◽  
Base Oil ◽  
Frictional Performance

In this study, we used a four-ball friction and wear testing machine to test the tribological properties of [HPy]BF4 ionic liquids (ILs), low-layer graphene (G), and IL and G compounds (IL/G) as lubricant additives at variousconcentrations, loads, and speeds. The morphology of the wear scar was characterized by a white-light interferometer and a scanning electron microscope (SEM). The results showed that the optimal concentrations of IL and G were 0.10[Formula: see text]wt.% and 0.05[Formula: see text]wt.%, respectively. When the IL concentration was 0.10[Formula: see text]wt.%, the friction coefficient and the wear scar diameter (WSD) reduced by approximately 18% and 8%, respectively, compared to the base oil. When the concentration of G was 0.05[Formula: see text]wt.%, the friction coefficient and WSD reduced by approximately 23% and 12%, respectively, compared to the base oil. After adding the optimal concentration of the IL/G composite additive under the same test conditions, the average friction coefficient of the steel ball reduced by approximately 30%, and the average WSD reduced by approximately 18%. IL/G nanoadditives could be easily attached to the pit area on the friction surface of the steel ball, which made the contact surface of the friction pair smoother and the area of the oil film bearing the load larger, compared to those using the base oil. These two combined phenomena promoted synergistic antifriction and antiwear effects, which significantly improved the frictional performance of the base oil.

scholarly journals Tribological Behaviour and Lubricating Mechanism of Tire Pyrolysis Oil

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 386
Author(s):  
Haseeb Yaqoob ◽  
Yew Heng Teoh ◽  
Farooq Sher ◽  
Muhammad Ahmad Jamil ◽  
Mirza Nuhanović ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Diesel Fuel ◽  
Wear Scar ◽  
Pyrolysis Oil ◽  
Tribological Behaviour ◽  
Wear Scar Diameter ◽  
Load Carrying ◽  
Scanning Electron ◽  
Lubricating Mechanism

The four-ball tester was used in this analysis to demonstrate the lubricity of tire pyrolysis oil (TPO). The tribological performance of the tire pyrolysis oil was compared with diesel fuel (DF) and their blends, DT10 (TPO 10%, Diesel 90%) and DT20 (TPO 20%, Diesel 80%). A scanning electron microscope (SEM) was used to investigate the wear scar. In contrast to diesel fuel, TPO demonstrated better antiwear behaviour in terms of higher load-carrying capacity. DT10, DT20, and TPO’s wear scar diameter (WSD) was 22.35%, 16.01%, and 31.99% smaller than that of diesel at 80 kg load, respectively. The scanning electron microscope micrographs showed that the TPO and DT10 had less wear than their counterparts.

scholarly journals Friction Reduction Capabilities of Silicate Compounds Used in an Engine Lubricant on Worn Surfaces

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Devendra Singh ◽  
G. D. Thakre ◽  
L. N. Sivakumar Konathala ◽  
V. V. D. N. Prasad
Keyword(s):  
Friction Coefficient ◽  
Wear Test ◽  
Magnesium Silicate ◽  
Wear Scar ◽  
Friction Reduction ◽  
Elemental Distribution ◽  
Wear Scar Diameter ◽  
Antiwear Properties ◽  
Worn Surfaces

Effects of magnesium silicate and alumina dispersed in engine lubricant on friction, wear, and tribosurface characteristics are studied under boundary and mixed lubrication conditions. Magnesium silicate and alumina, henceforth called as friction reducing compounds (FRC), were dispersed in engine lubricant in very low concentration of 0.01% weight/volume. Four-ball wear test rig was used to assess friction coefficient and wear scar diameter of balls lubricated with and without FRC based engine lubricant. Scanning electron microscopy (SEM) equipped with Energy Dispersive X-ray (EDX) was used to analyse the tribosurface properties and elemental distributions on worn surfaces of the balls. Test results revealed that FRC based engine lubricant increases friction coefficient but marginally reduces wear scar diameter of new balls, whereas, test on the worn-out balls running on FRC based engine lubricants shows 46% reduction in friction coefficient compared to the new balls running on engine lubricants without FRC. Investigations on tribosurfaces with respect to morphology and elemental distribution showed the presence of Si and O elements in micropores of the worn surfaces of the balls, indicating role of FRC in friction coefficient reduction and antiwear properties. These FRC based engine lubricants may be used in the in-use engines.

scholarly journals Tribological Performance Investigation of a Commercial Engine Oil Incorporating Reduced Graphene Oxide as Additive

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 386
Author(s):  
Hakan Kaleli ◽  
Selman Demirtaş ◽  
Veli Uysal ◽  
Ioannis Karnis ◽  
Minas M. Stylianakis ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Tribological Behavior ◽  
Control Sample ◽  
Protective Layer ◽  
Steel Ball ◽  
Carbon Accumulation ◽  
Engine Oil ◽  
Wear Scar Diameter ◽  
Reduced Graphene

We investigated the tribological behavior of commercialized, fully synthetic engine oil upon the incorporation of reduced graphene oxide in seven different concentrations between 0.01 and 0.2 wt %. Stability of the prepared samples was assessed by turbidimetry and dynamic light scattering measurements, and their tribological properties through a reciprocating tribometer, using a steel ball on special cut steel blocks. The addition of 0.02 wt % of reduced graphene oxide led to an improvement of the tribological behavior compared to the pristine engine oil, by significantly lowering the friction coefficient by 5% in the boundary lubrication regime. Both the surfaces and the reduced graphene oxide additive were thoroughly characterized by microscopic and optical spectroscopy techniques. We also verified that a protective layer was formed between the worn surfaces, due to the presence of reduced graphene oxide. Carbon accumulation and various additive elements such as Ca, Zn, S and P were detected on the rubbing surfaces of both the ball and the block through energy-dispersive X-ray spectroscopy. Finally, it was shown that the wear scar diameter on the surface of the steel ball was lower by 3%, upon testing the engine oil sample containing reduced graphene oxide at concentration 0.02 wt %, compared to the control sample.

scholarly journals Tribochemistry and EP Activity Assessment of Mo-S Complexes in Lithium-Base Greases

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Tarunendr Singh
Keyword(s):  
Electron Spectroscopy ◽  
Auger Electron ◽  
Wear Scar ◽  
Extreme Pressure ◽  
Flash Temperature ◽  
Wear Scar Diameter ◽  
Activity Assessment ◽  
Temperature Parameter ◽  
Ball Test ◽  
Base Grease

The blends of bis(1,5-diaryl-2,4-dithiomalonamido)dioxomolybdenum(VI) complexes in lithium-base grease are evaluated for their extreme pressure activity in a “four-ball test” using 12.7 mm diameter alloy steel ball specimen. The additive, bis(1,5-di-p-methoxyphenyl-2,4-dithiomalonamido)dioxomolybdenum(VI) and bis(1,5-di-p-chloro-phenyl-2,4-dithiomalonamido)dioxomolybdenum(VI) exhibited lower values of wear-scar diameter at higher load and higher values of weld load, flash temperature parameter, and pressure wear index as compared with lithium-base grease without additives. The greases fortified with the developed additives prevent rusting and corrosion of bearings while grease containing no additives did not pass these tests as per the standard tests. These greases have also better oxidation protection as compared to the grease that has no additive. The topography and tribochemistry of the wear-scar surface are carried out by means of scanning electron microscopy and Auger electron spectroscopy techniques, respectively.

A Conversion and Tribology Investigation on Used Ayurvedic Oil

2015 ◽  
Vol 813-814 ◽  
pp. 885-889 ◽  
Author(s):  
Ranganathan Balakumar ◽  
G. Sriram ◽  
S. Arumugam ◽  
V. Abhijith Koushal ◽  
Villa Sai Surya Venkatesh
Keyword(s):  
Fourier Transform ◽  
Methyl Ester ◽  
Ftir Spectroscopy ◽  
Diesel Fuel ◽  
Alternative Fuels ◽  
Fourier Transform Infrared ◽  
Wear Scar ◽  
Spectroscopy Analysis ◽  
Ic Engine ◽  
The Fourier Transform

Biofuel plays a major role in IC engine nowadays. Used Ayurvedic Oil (UAO) is one among the alternative fuels utilized. The preliminary property studies were carried out and the UAO had undergone simple Transesterification process to be converted to Used Ayurvedic Oil Methyl Ester (UAOME). The Fourier Transform Infrared (FTIR) spectroscopy analysis confirmed the UAO to UAOME conversion. The Trobological investigation on UAOME is also conducted using Four Ball Wear Tester. The results showed that lower wear scar was observed in UAOME comparatively with diesel. From the results it is clear that the UAO can be a novel partial substitute for diesel fuel.

Tribological and rheological properties of nanorods–Al2O3 as additives in grease

2018 ◽  
Vol 233 (4) ◽  
pp. 605-614 ◽  
Author(s):  
He Qiang ◽  
Tao Wang ◽  
Hongwen Qu ◽  
Yong Zhang ◽  
Anling Li ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Rheological Properties ◽  
Steel Surface ◽  
Wear Scar ◽  
Protective Film ◽  
Wear Scar Diameter ◽  
Lithium Grease ◽  
Rheological Behaviors

In this paper, the tribological and rheological behaviors of nanorods–Al2O3 as an additive in lithium grease at different concentrations were investigated. The morphology of the additive was determined. The improvement in the rheological properties after adding the nanorods was studied and illustrated by measuring the wear of the tested surfaces. The results showed that nanorods–Al2O3 can greatly improve the lubricating effect of grease. The grease with a 0.3 wt% content of nanorods–Al2O3 exhibited the lowest average friction coefficient and wear scar diameter. The worn steel surface was smooth and showed few furrows and grooves. Moreover, a correlation was found between the tribological and rheological properties of lithium grease. By increasing the temperature continuously, a chemical protective film was produced leading to the reduction in the friction coefficient of grease.

Antiwear and extreme pressure performance of castor oil with nano-additives

2017 ◽  
Vol 232 (9) ◽  
pp. 1055-1067 ◽  
Author(s):  
Rajeev Nayan Gupta ◽  
AP Harsha
Keyword(s):  
Castor Oil ◽  
Sodium Dodecyl ◽  
Wear Scar ◽  
Suspension Stability ◽  
Additive Concentration ◽  
Extreme Pressure ◽  
Wear Scar Diameter ◽  
Load Carrying ◽  
Nano Additives ◽  
Analytical Tools

The aim of the present study is to examine the antiwear, antifriction, and extreme pressure performance of castor oil with nano-additives by using a four-ball tester. CeO2 (≈90 nm) and polytetrafluroethylene (≈150 nm) nanoparticles were used as an additive in castor oil with four different concentrations in the range of 0.1–1.0% w/v. The suspension stability of the nanoparticles was improved by using sodium dodecyl sulfate as a dispersant. Different analytical tools were used to characterize the nanoparticles parameter (i.e. shape and size) as well as the worn surfaces. The additive concentration was optimized on the basis of tribological performance. The test results of antiwear and extreme pressure property have been reported on the basis of wear scar diameter and weld load, respectively. For the antiwear test, it was observed that the maximum reduction in the wear scar diameter was 37.4 and 35.3% at an optimum concentration of CeO2 and polytetrafluroethylene additive, respectively. Also, antifriction and load carrying properties of castor oil were significantly improved with the addition of nanoparticles as an additive in a small amount. The mechanism for such improvement in the tribological behavior has also been discussed.

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