Exploration of Talc nanoparticles to enhance the performance of Lithium grease

The tribological properties of Lithium grease specimens with different concentrations of Al2O3 nanoparticles were investigated using a pin on disc apparatus under different sliding speeds and normal loads. Results showed that Al2O3 nanoparticles enhanced the tribological properties of lithium grease and reduced the COF and wear scar width by approximately 57.9% and 47.5% respectively.

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Tribological behaviors of some novel dimercaptothiadiazole derivatives containing hydroxyl as multifunctional lubricant additives in biodegradable lithium grease

Industrial Lubrication and Tribology ◽

10.1108/ilt-08-2011-0065 ◽

2014 ◽

Vol 66 (1) ◽

pp. 51-61 ◽

Cited By ~ 1

Author(s):

Huan Chen ◽

Junhui Jiang ◽

Tianhui Ren ◽

Lei Zheng ◽

Yidong Zhao

Keyword(s):

Lubricant Additives ◽

Short Chain ◽

Lithium Grease ◽

Edge Structure ◽

Content Type ◽

Organic Sulfide ◽

Ferrous Sulfide ◽

Heterocyclic Derivatives ◽

Main Component ◽

Thermal Films

Purpose – In order to meet the requests of exploring environmental-friendly and multifunctional lubricant additives, some novel dimercaptothiadiazole derivatives containing hydroxyl are prepared and used as antiwear (AW) and extreme-pressure (EP) additives in biodegradable lithium grease. The paper aims to discuss these issues. Design/methodology/approach – The tribological performances of the grease samples containing these derivatives are evaluated by using a four-ball tester. X-ray absorption near edge structure (XANES) spectroscopy is used to analyze the chemistry of tribofilms under AW/EP regime, and thermal films are also considered for comparison. Findings – The tribological tests show that these derivatives are all effective in reducing wear, especially at lower additive concentrations, but they are basically failed in reducing friction. They are also helpful in improving the EP characteristic of the base grease. The thermal films generated by these derivatives are composed of adsorbed organic sulfide and ferrous sulfate, though for short-chain derivatives, organic sulfide is the only component at 5.0 wt.%. Ferrous sulfide is the main component of the tribofilms formed by these derivatives at various additive concentrations. But for short-chain derivatives, these tribofilms consist of ferrous sulfide and ferrous disulfide at 5.0 wt.%, and the appearance of disulfide suggests that the interfacial temperature between the upper ball and three lower balls under these conditions is considerably low. The EP films generated by short-chain derivatives are all composed of organic sulfide and ferrous sulfide, while for long-chain derivatives, ferrous sulfide is the main component. Originality/value – These low-toxic and oil-soluble dimercaptothiadiazole derivatives are effective in improving the tribological characteristic of the biodegradable lithium grease, and these heterocyclic derivatives may be good substitutes for some harmful traditional additives.

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Tribological Behavior of Carbon Nanotubes as an Additive on Lithium Grease

Journal of Tribology ◽

10.1115/1.4028225 ◽

2014 ◽

Vol 137 (1) ◽

Cited By ~ 49

Author(s):

Alaa Mohamed ◽

T. A. Osman ◽

A. Khattab ◽

M. Zaki

Keyword(s):

Carbon Nanotubes ◽

Arc Discharge ◽

Average Diameter ◽

Friction Reduction ◽

Lithium Grease ◽

X Ray ◽

Transmission Electron ◽

Boundary Film ◽

Load Carrying ◽

Worn Surface

Carbon nanotubes (CNTs) with 10 nm average diameter and 5 μm in length were synthesized by electric arc discharge. The morphology and structure of CNTs were characterized by high resolution transmission electron microscopy (HRTEM) and X-ray powder diffraction. The tribological properties of CNTs as an additive on lithium grease were evaluated with a four ball tester. The results show that the grease with CNTs exhibit good performance in antiwear (AW) and decrease the wear scare diameter (WSD) about 63%, decrease friction reduction about 81.5%, and increase the extreme pressure (EP) properties and load carrying capacity about 52% with only 1% wt. of CNTs added to lithium grease. The action mechanism was estimated through analysis of the worn surface with a scanning electron microscope (SEM) and energy dispersive X-ray (EDX). The results indicate that a boundary film mainly composed of CNTs, Cr, iron oxide, and other organic compounds was formed on the worn surface during the friction process.

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A Taguchi Approach on Influence of Graphite as an Anti-Wear Additive on the Performance of Lithium Grease

Procedia Manufacturing ◽

10.1016/j.promfg.2018.02.072 ◽

2018 ◽

Vol 20 ◽

pp. 487-492 ◽

Cited By ~ 2

Author(s):

Prashant Nagare ◽

Hari Kudal

Keyword(s):

Taguchi Approach ◽

Lithium Grease

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TRIBOLOGICAL PERFORMANCE OF LITHIUM GREASE DISPERSED BY SILCA NANO PARTICLES AND CARBON NANOTUBES

Journal of the Egyptian Society of Tribology ◽

10.21608/jest.2021.189027 ◽

2021 ◽

Vol 18 (3) ◽

pp. 23-34

Keyword(s):

Carbon Nanotubes ◽

Tribological Performance ◽

Nano Particles ◽

Lithium Grease

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Mechanical Contact Frequency Response Measurements

Journal of Tribology ◽

10.1115/1.1314601 ◽

2000 ◽

Vol 122 (4) ◽

pp. 828-833 ◽

Cited By ~ 3

Author(s):

S. S. Kupchenko ◽

D. P. Hess

Keyword(s):

Frequency Response ◽

Phase Lag ◽

Lithium Grease ◽

Mineral Oils ◽

Vibration Data ◽

Response Data ◽

Lubricated Contacts ◽

Wide Range ◽

Contact Frequency ◽

Dry Conditions

This paper presents friction frequency response measurements taken from a planar steel contact subjected to controlled random broadband normal vibration. Data are included from both dry and various lubricated contact conditions under different vibration input levels and different sliding velocities. Frequency response data for dry contacts are found to have nearly steady magnitude and negligible phase lag over a relatively wide range of frequencies. This suggests a coefficient of friction, independent of frequency but dependent on levels of normal acceleration and sliding velocity, may adequately define the dry contact frequency response. The frequency response data for lubricated contacts are mixed. For example, with MoS2 grease the frequency response may adequately be defined by a constant, as with dry conditions. However, frequency response data for contacts with pure mineral oils, mineral oils with additives, and lithium grease are found to be dependent on frequency. [S0742-4787(11)00101-9]

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