Tribological properties and action mechanism of a highly hydrolytically stable N-containing heterocyclic borate ester

2016 ◽  
Vol 68 (5) ◽  
pp. 569-576 ◽  
Author(s):  
Fu-Wang Yang ◽  
Jiang-Min Huang ◽  
Guan-Jun Zhang ◽  
Chenxi Zhang ◽  
Dong-Lan Sun ◽  
...  
Keyword(s):  
Tribological Properties ◽  
Hydrolytic Stability ◽  
Engine Oil ◽  
Wear Property ◽  
Extreme Pressure ◽  
Content Type ◽  
Base Oil ◽  
Borate Ester ◽  
Borate Esters ◽  
The Stability

Purpose The phosphorus and zinc contained in zinc dialkyl dithiophosphate (ZDDP) caused severe environment pollution and catalyst poison. Thus, the phosphorus-free additive, such as borate esters, has become one of studying hot topics in the area of oil additive. However, the stability of hydrolysis greatly limited the use of borate esters. The purpose of this paper is to improve the stability of hydrolysis by synthesizing a new kind of N-containing heterocyclic borate ester (MTTDB) as a lubricant additive. Design/methodology/approach The tribological properties of novel borate ester (MTTDB) as an additive in the base oil were studied by a four-ball machine. The element composition and chemical state of the tribofilm were investigated by scanning electron microscopy, energy dispersive spectrometer and X-ray photoelectron spectroscopy. Findings The results showed that the base oil lubricated by MTTDB exhibited high hydrolytic stability, good anti-wear property and excellent extreme pressure performance. When 2.5 per cent MTTDB was added into the 100N base oil, the smallest wear scar diameter (0.46 mm) was obtained. Furthermore, the decomposed borate ester, organic sulfide adsorbed on the worn surface was detected, and S element reacted with the steel surface and generated FeSO4, both of which contributed to the formation of the tribofilm. Originality/value Based on N-containing heterocyclic compounds, for instance, thiadiazole derivatives, introducing nitrogen and sulfur elements into borate ester, a new kind of N-containing heterocyclic borate ester (MTTDB) exhibited excellent property in hydrolysis stability, friction-reducing, anti-wear and extreme pressure. This synthesized method would be helpful for the borate ester used as additive in engine oil, gear oil and other industrial lubricants.

Preparation and tribological properties of a kind of lubricant containing cerium borate nanoparticles as additives

2019 ◽  
Vol 234 (11) ◽  
pp. 1789-1797 ◽  
Author(s):  
Lifeng Hao ◽  
Feng Cao ◽  
Zewen Jiang ◽  
Jiusheng Li ◽  
Tianhui Ren
Keyword(s):  
Tribological Properties ◽  
Photoelectron Spectroscopy ◽  
Lubricant Additive ◽  
Wear Property ◽  
Reaction Products ◽  
Tribochemical Reaction ◽  
Base Oil ◽  
Reducing Ability ◽  
Borate Ester ◽  
Friction Reducing

Oil-soluble compounds containing boron as lubricating additives were restricted by the hydrolysis of borate ester. In order to overcome this problem, cerium borate nanoparticles modified with oleic acid (O-CeB) as a potential substitute for conventional lubricant additive were studied in detail. The microstructures of the prepared nanoparticles were characterized. Tribological properties of cerium borate nanoparticles used as additive in base oil were evaluated, and the worn surface of the steel ball was investigated. The results show that O-CeB possesses better anti-wear ability at relatively higher concentration; in particular, it shows better friction-reducing ability under all these studied concentrations. Under higher load, its anti-wear property and friction-reducing property are better than that of Vanlube 289 in the base oil. Based on these results of interferometric surface profilometer and X-ray photoelectron spectroscopy, it can be deduced that a continuous resistance film containing depositions and the tribochemical reaction products was formed during the sliding process.

scholarly journals Effect of Size of Multiwalled Carbon Nanotubes Dispersed in Gear Oils for Improvement of Tribological Properties

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Kodanda Rama Rao Chebattina ◽  
V. Srinivas ◽  
N. Mohan Rao
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Ball Milling ◽  
Multiwalled Carbon Nanotubes ◽  
Tribological Properties ◽  
Extreme Pressure ◽  
Multiwalled Carbon ◽  
Pristine Mwcnts ◽  
Gear Oil ◽  
The Stability

The aim of the paper is to investigate the effect of size of multiwalled carbon nanotubes (MWCNTs) as additives for dispersion in gear oil to improve the tribological properties. Since long pristine MWCNTs tend to form clusters compromising dispersion stability, they are mildly processed in a ball mill to shorten the length and stabilized with a surfactant before dispersing in lubricant. Investigations are made to assess the effect of ball milling on the size and structure of MWCNTs using electron microscopy and Raman spectroscopy. The long and shortened MWCNTs are dispersed in EP 140 gear oil in 0.5% weight. The stability of the dispersed multiwalled carbon nanotubes is evaluated using light scattering techniques. The antiwear, antifriction, and extreme pressure properties of test oils are evaluated on a four-ball wear tester. It is found that ball milling of MWCNTs has a strong effect on the stability and tribological properties of the lubricant. From Raman spectroscopy, it is found that ball milling time of up to 10 hours did not produce any defects on the surface of MWCNTs. The stability of the lubricant and the antiwear, antifriction, and extreme pressure properties have improved significantly with dispersion shortened MWCNTs. Ball milling for longer periods produces defects on the surface of MWCNTs reducing their advantage as oil additives.

Effect of hexagonal boron nitride nanoparticles as an additive on the extreme pressure properties of engine oil

2016 ◽  
Vol 68 (4) ◽  
pp. 441-445 ◽  
Author(s):  
Muhammad Ilman Hakimi Chua Abdullah ◽  
Mohd Fadzli Bin Abdollah ◽  
Noreffendy Tamaldin ◽  
Hilmi Amiruddin ◽  
Nur Rashid Mat Nuri
Keyword(s):  
Diesel Engine ◽  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Experimental Studies ◽  
Engine Oil ◽  
Lubricating Oil ◽  
Extreme Pressure ◽  
Content Type ◽  
Load Carrying ◽  
Sonication Technique

Purpose This paper aims to investigate the effect of hexagonal boron nitride (hBN) nanoparticles on extreme pressure (EP) properties when used as an additive in lubricating oil. Design/methodology/approach The nano-oil was prepared by dispersing an optimal composition of 0.5 vol. per cent of 70 nm hBN in SAE 15W-40 diesel engine oil using a sonication technique. The tribological testing was performed using a four-ball tribometer according to the ASTM standard. Findings It was found that the nano-oil has a potential to decelerate the seizure point on the contact surfaces, where higher EP can be obtained. More adhesive wear was observed on the worn surfaces of ball bearing lubricated with SAE 15W-40 diesel engine oil as compared with the nano-oil lubrication. Originality/value The results of the experimental studies demonstrated the potential of hBN as an additive for improving the load-carrying ability of lubricating oil.

Effects of phosphorus-free antioxidants on oxidation stability and high-temperature tribological properties of lubricants

2017 ◽  
Vol 231 (12) ◽  
pp. 1527-1536 ◽  
Author(s):  
Wang Liping ◽  
Zhang Dongya ◽  
Wu Hongxing ◽  
Xie Youbai ◽  
Dong Guangneng
Keyword(s):  
Tribological Properties ◽  
Ternary Complex ◽  
Oxidation Stability ◽  
Service Performance ◽  
Engine Oil ◽  
Zinc Dialkyldithiophosphate ◽  
Scanning Calorimetry ◽  
Base Oil ◽  
Hindered Phenol ◽  
Standard Tests

Oxidation stability plays an important role on the engine oil service performance. In this paper, the phosphorus-free antioxidants of diphenylamine, hindered phenol and dibutyldithiocarbamate, combined with zinc dialkyldithiophosphate were added as antioxidants in the base oil and the fully formulated 5W-30 oil, and the oxidation stabilities were evaluated by pressurized differential scanning calorimetry and Romaszewski oil bench oxidation standard tests. Meanwhile, the tribological properties of the fresh and aged oils were evaluated by a SRV tribo-meter. The results indicated that (i) an optimal ternary complex antioxidant of dibutyldithiocarbamate: diphenylamine: hindered phenol (ratio of 2:1:2) displayed good antioxidation property, and (ii) the fully formulated 5W-30 oil containing optimized ratio phosphorus-free antioxidants had better tribological properties than the commercial SN 5W-30 oil.

The tribological performance of engineered micro-surface topography by picosecond laser on PEEK

2019 ◽  
Vol 72 (1) ◽  
pp. 172-179 ◽  
Author(s):  
Meiling Wang
Keyword(s):  
Tribological Properties ◽  
Design Methodology ◽  
Friction And Wear ◽  
Picosecond Laser ◽  
Wear Property ◽  
Content Type ◽  
Friction Curve ◽  
Micro Structures ◽  
Wear Tests ◽  
Friction And Wear Tests

Purpose The purpose of this study is to investigate the effect of engineered micro-structures on the tribological properties of metal-polyetheretherketone (PEEK) surface. Design/methodology/approach Circular dimples with diameters of 25 and 50 µm were designed and manufactured on PEEK plate specimens using picosecond laser. Reciprocating friction and wear tests on a ball-on-flat configuration were performed to evaluate the tribological properties of the designed micro-structures in dry contacts. The loading forces of 0.9 and 3 N were applied. Findings As a result, obvious fluctuations of coefficient of friction curve were observed in tribosystems consisting of non-textured and textured PEEK with circular dimples of 25 µm in diameter. GCr15 ball/textured PEEK plate specimens with circular dimples of 50 µm in diameter revealed a superior friction and wear property. Originality/value Different to the existing studies in which the tribopairs consist of hard bearing couples, this study investigated the tribological properties of the engineered micro-structures on the hard-on-soft bearing couples.

Synthesis and tribological properties of nanogrease

2018 ◽  
Vol 70 (3) ◽  
pp. 512-518 ◽  
Author(s):  
Alaa Mohamed ◽  
Mohamed Hamdy ◽  
Mohamed Bayoumi ◽  
Tarek Osman
Keyword(s):  
Electron Microscopy ◽  
Tribological Properties ◽  
Power Efficiency ◽  
New Technologies ◽  
Mechanical Equipment ◽  
Content Type ◽  
Base Oil ◽  
X Ray ◽  
Transmission Electron ◽  
Steel Balls

Purpose To enhance the tribological properties of nanogrease, one of the new technologies was used to synthesize a nanogrease having carbon nanotubes (CNTs) nanoparticles (NPs) with different concentrations. The microstructures of the synthesized NPs were characterized and evaluated by x-ray diffraction spectroscopy (XRD) and transmission electron microscopy (TEM). Tribological properties of the nanogrease were evaluated using a four-ball tester. The worn surface of four steel balls was investigated by scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX). Design/methodology/approach Grease was dissolved in chloroform (10 Wt.%), at 25 °C for 1 h. In parallel, functionalized CNTs with different volume concentrations (0.5, 1, 2 and 3 Wt.%) were dispersed in N, N-dimethylformamide. The mixture was stirred for 15 min and then sonicated (40 kHz, 150 W) for 30 min. After that, the mixture was added to the grease solution and magnetically stirred for 15 min and then sonicated for 2 h. Findings The results suggested that CNTs can enhance the antiwear and friction properties of nanogrease at 0.5 Wt.% CNTs to about 57 and 48 per cent, respectively. In addition, the weld load of the base oil containing 0.5 Wt.% CNTs was improved by 17 per cent compared with base grease. Originality/value This work describes the inexpensive and simple fabrication of nanogrease for improving the properties of lubricants, which improve power efficiency and extend lifetimes of mechanical equipment.

Preparation and tribological properties of the N-containing heterocyclic borate esters and Cu microparticles as lubricant additives in base oil

2017 ◽  
Vol 29 (6) ◽  
pp. 395-409 ◽  
Author(s):  
Mengnan Qu ◽  
Yali Yao ◽  
Jinmei He ◽  
Xuerui Ma ◽  
Shanshan Liu ◽  
...  
Keyword(s):  
Tribological Properties ◽  
Lubricant Additives ◽  
Base Oil ◽  
Borate Esters

Preparation and tribological properties of attapulgite – bentonite clay base grease

2014 ◽  
Vol 66 (4) ◽  
pp. 538-544 ◽  
Author(s):  
Tiedan Chen ◽  
Yanqiu Xia ◽  
Zhilu Liu ◽  
Zeyun Wang
Keyword(s):  
Tribological Properties ◽  
Bentonite Clay ◽  
Solid Particles ◽  
Lubricating Grease ◽  
Content Type ◽  
Base Oil ◽  
Dropping Point ◽  
Attapulgite Clay ◽  
Surface Modified ◽  
Base Grease

Purpose – The mixture of attapulgite and bentonite was used as a thickener, and polyalphaolefin was used as the base oil to prepare the new lubricating grease. Some solid particles such as Polytetrafluoroethene (PTFE), MoS2, nano-calcium carbonate and graphite were added in the new lubricating grease as anti-wear additives to investigate the tribological sensitivity. Design/methodology/approach – The new lubricating grease was evaluated by optimol-SRV reciprocating friction and wear tester, and the wear volumes were determined using a MicroXAM-3D. At the same time, the dropping point and the cone penetration were investigated and analyzed. The tribological properties of the new lubricating grease and the sensitivity of some solid lubricating additives to the new lubricating base grease were investigated; pure organic-bentonite and pure organic-attapulgite base grease were used as contrast. Findings – The new lubricating grease based on the surface-modified bentonite/attapulgite clay base grease was synthesized with a relatively high dropping point, and the mass ratio is 25/75 bentonite/attapulgite clay base grease, having a better tribological performance. MoS2 was used as an anti-wear additive that has good tribological sensitivity to the new lubricating base grease. Originality/value – The main innovative thought of this work lies in the mixture of attapulgite and bentonite used as thickener. A relevant report is not available at present.

Experimental analysis and modeling of viscosity and thermal conductivity of GNPs/SAE 5W40 nanolubricant

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Valéry Tusambila Wadi ◽  
Özkan Özmen ◽  
Mehmet Baki Karamış
Keyword(s):  
Thermal Conductivity ◽  
Peer Review ◽  
Dynamic Viscosity ◽  
Ann Model ◽  
Step Method ◽  
Rotational Viscometer ◽  
Content Type ◽  
Base Oil ◽  
Artificial Neural Network Ann ◽  
The Stability

Purpose The purpose of this study is to investigate thermal conductivity and dynamic viscosity of graphene nanoplatelet-based (GNP) nanolubricant. Design/methodology/approach Nanolubricants in concentrations of 0.025, 0.05, 0.1 and 0.5 Wt% were prepared by means of two-step method. The stability of nanolubricants was monitored by visual inspection and dynamic light scattering tests. Thermal conductivity and dynamic viscosity of nanolubricants in various temperatures between 25°C–70°C were measured with KD2-Pro analyser device and a rotational viscometer MRC VIS-8, respectively. A comparison between experimentally achieved results and those obtained from existing models was performed. New correlations were proposed and artificial neural network (ANN) model was used for predicting thermal conductivity and dynamic viscosity. Findings The designed nanolubricant showed good stability after at least 21 days. Thermal conductivity and dynamic viscosity increased with particles concentration. In addition, as the temperature increased, thermal conductivity increased but dynamic viscosity decreased. Compared to the base oil, maximum enhancements were achieved at 70°C with the concentration of 0.5 Wt.% for dynamic viscosity and at 55°C with the same concentration for thermal conductivity. Besides, ANN results showed better performance than proposed correlations. Practical implications This study outcomes will contribute to enhance thermophysical properties of conventional lubricating oils. Originality/value To the best of our knowledge, there is no paper related to experimental study, new correlations and modelling with ANN of thermal conductivity and dynamic viscosity of GNPs/SAE 5W40 nanolubricant in the available literature. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2020-0088/

scholarly journals SYNERGISTIC TRIBOLOGICAL PROPERTIES OF SYNTHETIC MAGNESIUM SILICATE HYDROXIDE COMBINED WITH AMPHIPHILIC MOLECULES

2019 ◽  
Vol 17 (1) ◽  
pp. 65 ◽  
Author(s):  
Bin Wang ◽  
Qiu Ying Chang ◽  
Kai Gao
Keyword(s):  
Molecular Dynamics ◽  
Tribological Properties ◽  
Molecular Layer ◽  
Magnesium Silicate ◽  
Nonequilibrium Molecular Dynamics ◽  
Wear Property ◽  
Base Oil ◽  
Amphiphilic Molecules ◽  
Test Conditions ◽  
Worn Surfaces

This paper reports the synthesis of magnesium silicate hydroxide (MSH) nanoparticles and their synergistic tribological properties combined with amphiphilic molecules (AMs) as additives in base oil. This combination reduces wear losses substantially due to the formation of a double well-arranged molecular layer or tribofilm on the rubbing surfaces under certain test conditions. From the results of nonequilibrium molecular dynamics (NEMD) simulations, lamellate MSH nanoparticles provide a medium for the adsorption of AMs thus further decreasing the contact of rough peaks. In addition, with the increase of load, a tribofilm containing element Mg, Si, O forms on the worn surfaces and greatly improves the anti-wear property of base oil.

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