Improved tribological and bearing vibration performance of calcium sulfonate complex grease dispersed with MoS<sub>2</sub> and oxide nanoparticles

Yin

Proceedings of the Institution of Mechanical Engineers, Part C:

et al. 2023

In this study, polydopamine and silver-modified graphene oxide (Ag/PGO) were prepared using a one-step method, and the effects of Ag/PGO as a lubricating oil additive on the viscosity, thermal conductivity, and lubricating performance of lubricating oil were studied. The influence of additive lubricating oil on the temperature increase and vibration of a high-speed motorized spindle was studied through a motorized spindle experiment. The results showed that the addition of Ag/PGO nanocomposites could improve the thermophysical properties and lubricating properties of the lubricating oil. The Ag/PGO nanoparticles deposited on the friction surface formed a friction protective film, which prevented direct contact between the friction pairs and effectively reduced the heat generated through friction and micro-peak collision during bearing operation. The lubricating oil containing Ag/PGO had high thermal conductivity and a good heat dissipation effect in convection heat transfer in the bearing cavity. The deposition and repair of nanoparticles could improve the micro-morphology of the friction surface and reduce the high-frequency amplitude of the motorized spindle.

“…35 Finally, like the lubrication mechanism of Ag/PGO, the deposition of nanoparticles improved the friction conditions. 19,36…”

Section: Vibration Reduction Mechanism Of the Lubricating Oil Contain...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of silver/polydopamine graphene oxide as lubricating oil additive on temperature rise and vibration of motorized spindle

Yin

Proceedings of the Institution of Mechanical Engineers, Part C:

et al. 2023

“…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%

“…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]). This can not only improve the tribological performance of CSCG but also suppress bearing vibration.…”

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

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.

“…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

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.