Tribological Behavior of WS2 Nanoparticles as Additives in Calcium Sulfonate Complex–Polyurea Grease

Zhang, Hong; Mo, Yimin; Lv, Juncheng; Wang, Jun

doi:10.3390/lubricants11060259

Cited by 5 publications

(5 citation statements)

References 33 publications

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“…Figure 8(a) shows the full XPS spectrum under pure lithium grease lubrication, in which it can be seen that the main chemical Figure 4 The morphologies and AWSD of the lower steel balls at 392 N and rotation speed 1,200 rpm for 30 min Lubrication properties of lithium grease components of the boundary lubrication film are Fe, C, O, Si, P and some inorganic metal elements from the grease. According to the relevant literatures (Liu et al, 2002;Hu et al, 2015;Li et al, 2018;Zhang et al, 2018;Yan et al, 2023b) and the NIST (National Institute of Standards and Technology) XP S database (Alexander et al, 2023). In the spectrum of C1s in Figure 8(b), the peak at 284.8 eV belongs to the -C-C-single bond, while the peaks at 286.5 eV and 288.5 eV belong to hydroxyl (-OH) and carboxyl (-COOH) groups in carbon-containing organic matter, respectively.…”

Section: Surface Characterization Of Wear Scarsmentioning

confidence: 99%

“…When only [HMIM]PF 6 is added for lubrication, as shown in Figure 10(b), it can be adsorbed on the surface of the friction subsurface to form a boundary lubrication film, preventing the friction sub-interface from direct contact and effectively reducing the coefficient of friction and surface wear (Huang et al, 2010;Liu et al, 2020). Moreover, under severe friction conditions, it will generate anti-wear substances such as FePO 4 and FeF 3 with the base material to reduce wear (Zhang et al, 2018). However, the stability of the adsorption membrane is poor, and with the accumulation of heat during the friction process, the adsorbed [HMIM]PF 6 detaches or decomposes, leading to the rupture of the adsorption membrane.…”

Section: Friction and Wear Mechanism Analysismentioning

confidence: 99%

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Influence of ionic liquid/liquid metals on the lubrication properties of lithium grease

Wen,

Hu,

Fei

et al. 2024

ILT

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Purpose This paper aims to use an ionic liquid (IL, [HMIM]PF6) to improve the lubrication performance of liquid metal (LM) as a lithium grease additive and to expand the application range of LM. Design/methodology/approach In this paper, the different mass ratios of [HMIM]PF6/LM mixtures were added into the lithium grease on a four-ball tribo-meter to investigate the effects of its tribological behavior. Scanning electron mircoscope/energy dispersive spectroscopy and X-ray photoelectron spectroscopy were used to reveal the anti-wear and friction-reducing mechanism of the additives. Findings When the load was used at 461 N, the average coefficient of friction (ACOF) and average wear scar diameter (AWSD) of steel ball Lubricated with grease with an optimal ratio of 2:3 ([HMIM]PF6/LM) were reduced by 32.8% and 30.5%, respectively. Friction and wear mechanisms are ascribed to friction-induced additive components that can simultaneously form a composite lubrication film consisting of FePO4, FeF3, Ga2O3, In2O3 and SnO2. Research limitations/implications Compared with the pure lithium-based grease, when [HMIM]PF6/LM was added with an optimal ratio of 2:3, the ACOF and AWSD were reduced by 12.4% from 0.097 to 0.085 and 23.8% from 552.117 µm to 420.590 µm under 392 N, respectively. When at 461 N, the ACOF and AWSD of steel ball were reduced by 32.8% from 0.122 to 0.082 and 30.5% from 715.714 µm to 497.472 µm, respectively. It was shown that the simultaneous addition of LM and [HMIM]PF6 can form a composite lubrication film consisting of FePO4, FeF3, Ga2O3, In2O3 and SnO2. Originality/value In this paper, [HMIM]P F6 is added with LM simultaneously to improve the lubrication properties of lithium grease, and expand the application scope of LM. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2024-0017/

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Section: Surface Characterization Of Wear Scarsmentioning

confidence: 99%

Section: Friction and Wear Mechanism Analysismentioning

confidence: 99%

Influence of ionic liquid/liquid metals on the lubrication properties of lithium grease

Wen,

Hu,

Fei

et al. 2024

ILT

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“…As shown in Table 3, the factors that may affect the tribological properties and service life of lubricating grease during the preparation process of CSCPG are listed, including the proportion of three thickening agents [29]: overbased calcium sulfonate T106A (coded A), polyurea thickening agent (coded C), and composite calcium soap (coded D); base oil 40 • C kinematic viscosity (coded B) [14]; the proportion of the content of the two additives: antioxidant (coded E) [30] and nano-solid friction reducers [10][11][12] (coded F); reaction time: conversion reaction time T 1 (coded G), thickening reaction time T 3 (coded H); reaction temperature: conversion reaction temperature t 1 (coded J), thickening reaction temperature t 3 (coded K), and grinding gap (coded L) during post-treatment [31]. Table 3 also provides the range of values for each factor, where the initial value refers to the values of each factor before optimization, and the maximum and minimum values are the allowable range of values for each factor obtained based on experience.…”

Section: Experimental Designmentioning

confidence: 99%

“…Therefore, many researchers have used nano-solid friction reducers to improve the tribological properties of CSCG. WS 2 nanoparticles can effectively reduce the friction coefficient of lubricating grease, which is mainly attributed to the adsorption and frictional chemical reactions between WS 2 nanoparticles and the matrix [10]. Multiple combinations of nanoparticles are added to CSCG (such as the combination of hexagonal boron nitride and nano-Al 2 O 3 [11] or the combination of MoS 2 , CuO, SiO 2 , and Al 2 O 3 nanoparticles [12]).…”

Section: Introductionmentioning

confidence: 99%

Optimization of the Tribological Performance and Service Life of Calcium Sulfonate Complex—Polyurea Grease Based on Unreplicated Saturated Factorial Design

Zhang,

Mo,

Liu

et al. 2023

Lubricants

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In order to further extend the service life of calcium sulfonate complex–polyurea grease (CSCPG) while ensuring its tribological performance, this article starts with the production of raw materials and the preparation process of the grease and explores the factors that significantly affect the tribological performance and service life of CSCPG based on unreplicated saturated factorial design (USFD). The Kriging prediction model is used along with the optimization objectives of friction coefficient and service life, and nondominated sorting genetic algorithm II (NSGA-II) was used for a multi-objective optimization solution. The tribological and service life tests were conducted before and after optimization. The results show that the viscosity of the base oil and the content of the nano-solid friction reducers have a significant impact on the tribological properties of CSCPG. The content of polyurea thickeners and antioxidants, as well as the thickening reaction temperature, have a significant impact on the service life of CSCPG. When the friction coefficient and service life are optimized as objectives and are compared to the initial group, the friction coefficient of CSCPG could be reduced by 5.3%, and the service life could be extended by 3.8%. The Kriging prediction model based on USFD has high accuracy and can be used to guide the preparation and performance optimization of CSCPG.

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“…Additional tribochemical and layer-formation studies were performed with PM-IRRAS spectroscopy [11,12] and a ToF-SIMS analysis [13,14]. The specific effects and properties of OBCS occurring in the vehicle industry were also investigated as its interaction with ZDDP in PAO base lubricant [15,16], its influence of water on the tribological properties in transmission fluids [17] and as an additive in complex greases with nanoparticles [18,19].…”

Section: Introductionmentioning

confidence: 99%

Tribological Investigation of the Effect of Nanosized Transition Metal Oxides on a Base Oil Containing Overbased Calcium Sulfonate

2023

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In this study, copper(II) oxide, titanium dioxide and yttrium(III) oxide nanoparticles were added to Group III-type base oil formulated with overbased calcium sulfonate. The nanosized oxides were treated with ethyl oleate surface modification. The tribological properties of the homogenized oil samples were tested on a linear oscillating tribometer. Friction was continuously monitored during the tribological tests. A surface analysis was performed on the worn samples: the amount of wear was determined using a digital optical and confocal microscope. The type of wear was examined with a scanning electron microscope, while the additives adhered to the surface were examined with energy-dispersive X-ray spectroscopy. From the results of the measurements, it can be concluded that the surface-modified nanoparticles worked well with the overbased calcium sulfonate and significantly reduced both wear and friction. In the present tribology system, the optimal concentration of all three oxide ceramic nanoadditives is 0.4 wt%. By using oxide nanoparticles, friction can be reduced by up to 15% and the wear volume by up to 77%. Overbased calcium sulfonate and oxide ceramic nanoparticles together form a lower friction anti-wear boundary layer on the worn surfaces. The results of the tests represent another step toward the applicability of these nanoparticles in commercial engine lubricants. It is advisable to further investigate the possibility of formulating nanoparticles into the oil.

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Tribological Behavior of WS2 Nanoparticles as Additives in Calcium Sulfonate Complex–Polyurea Grease

Cited by 5 publications

References 33 publications

Influence of ionic liquid/liquid metals on the lubrication properties of lithium grease

Influence of ionic liquid/liquid metals on the lubrication properties of lithium grease

Optimization of the Tribological Performance and Service Life of Calcium Sulfonate Complex—Polyurea Grease Based on Unreplicated Saturated Factorial Design

Tribological Investigation of the Effect of Nanosized Transition Metal Oxides on a Base Oil Containing Overbased Calcium Sulfonate

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