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

Tribological Properties of Flame Sprayed Hexagonal Boron Nitride/Polyetheretherketone Coatings

2011 ◽  
Vol 410 ◽  
pp. 333-336 ◽  
Author(s):  
Jirasak Tharajak ◽  
Tippaban Palathai ◽  
Narongrit Sombatsompop
Keyword(s):  
Boron Nitride ◽  
Tribological Properties ◽  
Hexagonal Boron Nitride ◽  
Steel Substrate ◽  
Spray Coating ◽  
Wear Test ◽  
Flame Spray ◽  
Composite Powders ◽  
Wear Rates ◽  
Peek Composite

Hexagonal boron nitride (h-BN)/polyetheretherketone (PEEK) composite powders were deposited on carbon steel substrate via the flame spray coating technique. The content of hexagonal boron nitride with a mean particle size of 0.5 micrometer was varied from 2 to 8 wt% in this work. Tribological properties, namely specific wear rate and friction coefficient, at room temperature, 100 °C and 200°C were performed using Ball-on-Disc sliding wear test. At elevated temperature, h-BN could result in marked decrease in the friction coefficients and specific wear rates.

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.

scholarly journals Research on the Influence of the Manufacturing Process Conditions of Iron Sintered with the Addition of Layered Lubricating Materials on its Selected Properties

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4782
Author(s):  
Wieslaw Urbaniak ◽  
Tomasz Majewski ◽  
Ryszard Wozniak ◽  
Judyta Sienkiewicz ◽  
Jozef Kubik ◽  
...  
Keyword(s):  
Particle Size ◽  
Boron Nitride ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Hexagonal Boron Nitride ◽  
Average Particle Size ◽  
Layered Materials ◽  
Process Conditions ◽  
Average Particle ◽  
Average Grain Size

The purpose of the conducted experiments was to test the selected properties of materials intended for porous sintered bearings containing layered materials in the form of powders with an average particle size of 0.5–1.5 μm, with very good tribological properties. The subject of the research was a sinter based on iron powder with the addition of layered materials; molybdenum disulfide MoS2 (average particle size 1.5 μm), tungsten disulfide WS2 (average particle size 0.6 μm), hexagonal boron nitride, h-BN (average particle size 0.5 and 1.5 μm) with two different porosities. The article presents the results of density and porosity tests, compressive strength, metallographic and tribological tests and the assessment of changes in the surface condition occurring during the long storage period. The use of layered additives allows for an approximately 20% lower coefficient of friction. In the case of sulfides, the technological process of pressing 250 MPa, 350 MPa, and sintering at a temperature of 1120 °C allows us to obtain a material with good strength and tribological properties, better than in the case of h-BN. However, the main problem is the appearance of elements from the decomposition of sulfide compounds in the material matrix, which results in rapid material degradation. In hexagonal boron nitride, such disintegration under these conditions does not occur; the material as observed does not degrade. In this case, the material is characterized by lower hardness, resulting from a different behavior of hexagonal boron nitride in the pressing and sintering process; in this case, pressing at a pressure of 350 MPa seems to be too low. However, taking into account that even with these technological parameters, the obtained material containing 2.5% h-BN with an average grain size of 1.5 μm allowed obtaining a coefficient of friction at the level of 0.41, which, with very good material durability, seems to be very positive news before further tests.

scholarly journals Rapeseed oil additivated with hexagonal boron nitride

2020 ◽  
Vol 12 (2) ◽  
pp. 63-72
Author(s):  
Traian Florian IONESCU ◽  
Adrian-Alin SORCARU ◽  
Dionis GUGLEA ◽  
George Catalin CRISTEA ◽  
Constantin GEORGESCU ◽  
...  
Keyword(s):  
Particle Size ◽  
Friction Coefficient ◽  
Boron Nitride ◽  
Rapeseed Oil ◽  
Mass Concentration ◽  
Hexagonal Boron Nitride ◽  
Average Particle Size ◽  
Average Particle ◽  
Test Parameters ◽  
Tribological Parameters

This paper presents the influence of hexagonal boron nitride (hBN) as additive in refined rapeseed oil in different mass concentration of 0.25%wt, 0.5%wt and 1%wt on the tribological parameters, obtained on a four-ball machine. The test parameters were load: 100 N, 200 N and 300 N and the rotational speed 1000 rpm, 1400 rpm and 1800 rpm, corresponding to the following sliding speed, 0.38 m/s, 0.53 m/s and 0.69 m/s, respectively. The average particle size of hBN is 14 nm. For the tested ranges of the parameters, the additivation of rapeseed oil with hBN does not improve the friction coefficient, but the wear rate of WSD seems to be less sensitive for the more severe regimes when the vegetal oil is additivated.

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.

Effects of Abrasive Particles on Lubricating Property of Oil-in-Water (O/W) Emulsions for Cold-Rolled Strip

2020 ◽  
Vol 861 ◽  
pp. 344-348
Author(s):  
Yan Li ◽  
Lei Xia ◽  
Ren Dong Liu ◽  
Rong Sheng Sun ◽  
Jian Jun Zhang ◽  
...  
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Testing Machine ◽  
Wear Scar ◽  
Wear Testing ◽  
Rolled Strip ◽  
Average Particle ◽  
Wear Scar Diameter ◽  
Abrasive Particles ◽  
Lubrication Performance

The abrasive particles in the working emulsion were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The wettability and lubricating properties of different emulsion samples were tested by MRS-10E four-ball friction and wear testing machine. The results show that the average particle size of the abrasive particles in the working emulsion is 2.72 μm, the smallest particle size of the abrasive particles is 0.36μm, and the largest size of the abrasive particles is 6.57μm. Furthermore, the abrasive particles can increase the internal friction of emulsions, which leads to the increasing wetting Angle. The abrasive particles cause the lubrication performance of working emulsion to decrease, which eventually leads to larger wear scar diameter and the worse morphology of wear scar on the tested ball.

scholarly journals Preparation and Tribological Properties of Carbon-Coated WS2 Nanosheets

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2835 ◽  
Author(s):  
Zheng Li ◽  
Fanshan Meng ◽  
Haohao Ding ◽  
Wenjian Wang ◽  
Qiyue Liu
Keyword(s):  
Tribological Properties ◽  
Friction And Wear ◽  
Hydrothermal Reaction ◽  
Matrix Material ◽  
Lubricant Additive ◽  
Wear Scar ◽  
Protective Film ◽  
Wear Scar Diameter ◽  
Base Oil ◽  
Carbon Coated

WS2-C is produced from a hydrothermal reaction, in which WS2 nano-sheets are coated with carbon, using glucose as the carbon source. In order to investigate the tribological properties of WS2-C as a lubricant additive, WS2-C was modified by surfactant Span80, and friction tests were carried out on an MRS-10A four-ball friction and wear tester. The results show that Span80 can promote the dispersibility of WS2-C effectively in base oil. Adding an appropriate concentration of WS2-C can improve the anti-wear and anti-friction performance of the base oil. The friction coefficient reached its lowest point upon adding 0.1 wt % WS2-C, reduced by 16.7% compared to the base oil. Meanwhile, the wear scar diameter reached its minimum with 0.15 wt % WS2, decreasing by 26.45%. Moreover, at this concentration, the depth and width of the groove and the surface roughness on the wear scar achieved their minimum. It is concluded that WS2-C dispersed in oil could enter friction pairs to avoid their direct contact, thereby effectively reducing friction and wear. At the same time, WS2-C reacts with the friction matrix material to form a protective film, composed of C, Fe2O3, FeSO4, WO3, and WS2, repairing the worn surface.

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