Dependence of Lithium Grease Dropping Points on Solubility Parameter of Oil Component

1966 ◽  
Vol 5 (2) ◽  
pp. 198-202 ◽  
Author(s):  
R. N. Bolster ◽  
R. C. Little
Keyword(s):  
Solubility Parameter ◽  
Lithium Grease ◽  
Dropping Points

scholarly journals Tribological Properties of Al2O3 Nanoparticles as Lithium Grease Additives

Lubricants ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 9
Author(s):  
Ahmed Nabhan ◽  
Ahmed Rashed ◽  
Nouby M. Ghazaly ◽  
Jamil Abdo ◽  
M. Danish Haneef
Keyword(s):  
Tribological Properties ◽  
Wear Scar ◽  
Al2o3 Nanoparticles ◽  
Lithium Grease ◽  
Pin On Disc ◽  
Scar Width

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.

A new expanded solubility parameter approach

2012 ◽  
Vol 426 (1-2) ◽  
pp. 29-43 ◽  
Author(s):  
Emmanuel Stefanis ◽  
Costas Panayiotou
Keyword(s):  
Solubility Parameter ◽  
Parameter Approach

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

2014 ◽  
Vol 66 (1) ◽  
pp. 51-61 ◽  
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.

Tribological Behavior of Carbon Nanotubes as an Additive on Lithium Grease

2014 ◽  
Vol 137 (1) ◽  
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.

Asphaltenes subfractions characterization and calculation of their solubility parameter using ESI(-) FT-ICR MS: Part II

Fuel ◽  
2022 ◽  
Vol 312 ◽  
pp. 122864
Author(s):  
Fernanda E. Pinto ◽  
Victor R. Fonseca ◽  
Lindamara M. Souza ◽  
Luciana A. Terra ◽  
Sreedhar Subramanian ◽  
...  
Keyword(s):  
Solubility Parameter ◽  
Ft Icr Ms ◽  
Ft Icr
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