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.

Microstructure, nano-mechanical characterization, and fretting wear behavior of plasma surface Cr-Nb alloying on γ-TiAl

2020 ◽  
pp. 135065012093983
Author(s):  
Dongbo Wei ◽  
Fengkun Li ◽  
Xiangfei Wei ◽  
Tomasz Liskiewicz ◽  
Krzysztof J Kubiak ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Behavior ◽  
Wear Test ◽  
Wear Scar ◽  
Fretting Wear ◽  
Friction Behavior ◽  
Plasma Surface ◽  
Nb Alloying

In this study, surface Cr-Nb alloying was realized on γ-TiAl using double glow plasma hollow cathode discharge technique. An inter-diffusion layer was generated under the surface, composed of Cr2Nb intermetallic compounds. After Cr-Nb alloying, the surface nanohardness of γ-TiAl increased from 5.65 to 11.61 GPa. The surface H/E and H3/E2 increased from 3.37 to 5.98 and from 0.64 to 4.15, respectively. Cr-Nb alloying and its effect on fretting wear were investigated. The surface treatment resulted in improved plastic deformation and fretting wear resistance of γ-TiAl. The fretting wear test showed that an average friction coefficient of γ-TiAl against Si3N4 ball was significantly decreased after Cr-Nb alloying. The fluctuation of friction coefficient during running-in stage was significantly improved. The friction behavior of both γ-TiAl before and after Cr-Nb alloying could be divided into distinctive stages including formation of debris, flaking, formation of crack, and delamination. It was observed that the high hardness, resistance to plastic deformation, and fatigue resistance of γ-TiAl after Cr-Nb alloying could inhibit the formation of debris and delamination during friction test. The fretting wear scar area and the maximum wear scar depth were decreased, indicating that the wear resistance of γ-TiAl has been greatly improved after Cr-Nb alloying. The results indicated that plasma surface Cr-Nb alloying is an effective way for improving the fretting wear resistance of γ-TiAl in aviation area.

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.

scholarly journals Examination of lubricity properties of mineral base oil, containing nanoparticles of hexagonal boron nitride, and evaluation of the influence of surfactants on their sedimentation

2020 ◽  
Vol 69 (4) ◽  
pp. 15-41
Author(s):  
Arkadiusz Chodkiewicz ◽  
Tadeusz Kałdoński
Keyword(s):  
Particle Size ◽  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Wear Test ◽  
Solid Particles ◽  
Wear Scar ◽  
Wear Scar Diameter ◽  
Load Curve ◽  
Base Oil ◽  
Mineral Base

The article presents the results of tests on the lubricity properties of SN150 base oil containing hexagonal boron nitride (h-BN) of different granulation. The boron nitride with a particle size below 100 nm and the second one with a particle size below 25 μm were used. The lubricity tests were carried out on a four-ball apparatus. The methodology of these tests was determined on the basis of the normative document PN-EN ISO 20623: 2018-02, which contains the following parameters characterising the lubricity: initial seizure load ISL [N], weld load WL [N], load-wear index LWI [N], mean wear scar diameter MWSD [mm] obtained in a long duration wear test under a specified load; wear-load curve, i.e., the dependence of the mean wear scar diameter on the load, was also performed. Tests were also carried out to check the influence of selected surfactants on the sedimentation process of hexagonal boron nitride in the SN150 mineral base oil. Based on the conducted research and their analysis, it was found that hexagonal boron nitride has a positive effect on the lubricating properties of the base oil; better results were obtained for the boron nano-nitride with a particle size below 100 nm. It was also found that the problem of sedimentation of the solid particles of hexagonal boron nitride was solved by the addition of succinimide dispersant. Keywords: tribology, lubricity, boron nitride, surfactants, sedimentation

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.

Ultra-low wear and anti-oxidation properties of microcrystalline graphite oxide-magnesium silicate hydroxide composite nanoadditives in the poly-alpha-olefin base oil

2021 ◽  
pp. 1-23
Author(s):  
Wang Kai ◽  
Qiuying Chang ◽  
Rongqin Gao
Keyword(s):  
Graphite Oxide ◽  
Photoelectron Spectroscopy ◽  
Hydrothermal Process ◽  
Magnesium Silicate ◽  
Wear Scar ◽  
Wear Properties ◽  
Wear Scar Diameter ◽  
Base Oil ◽  
X Ray ◽  
Alpha Olefin

Abstract Graphite-based materials and hydrothermal synthetic magnesium silicate hydroxide (MSH) had shown outstanding performances as lubricant additives. In this paper, microcrystalline graphite oxide-magnesium silicate hydroxide (MGO-MSH) composite additives using pre-oxidized MGO as one of the precursors were prepared at a mild hydration condition, and their tribological properties in poly-alpha-olefin oil (PAO 10) were demonstrated by a four-ball tester. The tribological results showed that the optimal concentration of MGO-MSH in oil was 0.3 wt% under 600 N, 600 rpm. Meanwhile, the average wear scar diameter of the ball samples tested in composite-suspending oil was reduced by 36.3% compared with that obtained by pure PAO 10. By means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Raman spectra, and X-ray photoelectron spectroscopy (XPS), it was verified that MGO was involved in the synthesis of MSH, and MSH was anchored on MGO during the hydrothermal process. In addition, it was confirmed that carbon-containing tribo-film was formed on the smooth wear region of the wear scar, and was of excellent anti-oxidation wear properties.

Effect of Ultrasonic Vibration on the Friction and Wear Properties of GCr15/45# Steel Frictional Pairs Lubricated by n-Al2O3 Additives

2012 ◽  
Vol 538-541 ◽  
pp. 1920-1923
Author(s):  
Yu Lin Qiao ◽  
Shan Lin Yang ◽  
Yan Zang ◽  
Xin Yu Dong ◽  
Qing Sheng Cui
Keyword(s):  
Friction Coefficient ◽  
Ultrasonic Vibration ◽  
Photoelectron Spectroscopy ◽  
Friction And Wear ◽  
Ball Bearing ◽  
Wear Scar ◽  
Friction Reduction ◽  
Wear Volume ◽  
Wear Properties ◽  
Friction And Wear Properties

The friction and wear properties of GCr15/45# steel frictional pairs lubricated by n- Al2O3 additives under ultrasonic vibration or not were studied. The scanning electron microscope(SEM), X-ray photoelectron spectroscopy(XPS) and energy dispersive spectrometer (EDS) were carried out to analyse the wear scar surface. The effect mechanism of ultrasonic vibration on friction pairs was discussed. The results indicated that ultrasonic vibration could decrease the friction and wear of GCr15/45# friction pairs, when the content of n-Al2O3 was 0.5wt%, the effect of ultrasonic vibration on friction pairs was most obvious. The friction coefficient, wear volume and wear scar depth under ultrasonic vibration decreased 10%, 34% and 13%, respectively. The friction reduction and anti-wear mechanism of n-Al2O3 was single “micro ball bearing” without ultrasonic vibration, and it changed to “micro ball bearing” and adsorption penetration film with ultrasonic vibration, so the friction coefficient and wear volume was reduced.

Effects of Different Load with Vary Lubricant on the Friction Coefficient and Wear Rate Using Pin on Disk Tribometer

2016 ◽  
Vol 819 ◽  
pp. 495-498 ◽  
Author(s):  
Samion Syahrullail ◽  
Norawzi Nuraliza
Keyword(s):  
Wear Rate ◽  
High Speed ◽  
Palm Olein ◽  
Surface Damage ◽  
Wear Scar ◽  
Friction Reduction ◽  
Wear Properties ◽  
Wear Scar Diameter ◽  
Pin On Disk ◽  
The Impact

A study has been created on the wear rate and friction constant for various material under the impact of load and material where the equipment pin on disk has been used to investigate the specification on the wear and constant of friction (COF) theory. The issues occur because of the metal-to-metal contact once interaction between two surfaces creates friction, wear and heat. It’ll cause every element life shortened, economically wasted, surface damage and cracks. This paper evaluates via pin on disc tribometer using SKD II and aluminum alloy, A 5083 as work pieces material. The test was tested using different type of lubricant (palm olein and mineral based oil) with different load. The result shows palm olein is more than mineral-based oil for constant friction as sliding speed increased and wear scar diameter lubricated with palm olein lower at low and high speed compared to the oil. As a conclusion, palm olein has better performance properties in terms of friction reduction (coefficient of friction) and wear resistance (anti-wear properties) at low and high speed. Pin that lubricated with palm olein showed small wear scar diameter compared to the mineral based oil. Therefore, palm olein has risk to use as a lubricant of mating components.

Influence of ZrO2 Nanoparticle as Additive on Tribological Property of Lithium Grease

2010 ◽  
Vol 26-28 ◽  
pp. 83-87 ◽  
Author(s):  
Xin Tao Xia ◽  
Ya Ping Zhang ◽  
Yong Zhen Zhang ◽  
Shi Chao Chen
Keyword(s):  
Friction Coefficient ◽  
Tribological Property ◽  
Mass Fraction ◽  
Friction And Wear ◽  
Wear Scar ◽  
Zro2 Nanoparticles ◽  
Wear Scar Diameter ◽  
Lithium Grease ◽  
Mass Fractions

The experiment on the friction and wear of the lithium grease is done by choosing the ZrO2 nanoparticles as the additive in order to study the change of the tribological property of the lithium grease. The friction coefficient decreases by over 30% if the ZrO2 nanoparticles with the mass fractions of 0.25% and 0.5% are used as the additive. The ZrO2 nanoparticles with the mass fraction of 0.25% and 0.5% reach the best result and the wear scar diameter can decrease by 48.8% and 46.5%, respectively.

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.

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