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Article
Publication date: 1 May 1976

OVER the years lithium soap greases have earned a reputation of providing excellent service under a wide variety of operating conditions. Since their introduction in the early…

Abstract

OVER the years lithium soap greases have earned a reputation of providing excellent service under a wide variety of operating conditions. Since their introduction in the early 1950s, lithium soap greases have served the market well, being especially suitable for both automotive and industrial multipurpose applications. Their performance has enabled them to grow in commercial importance to the point where they now account for over half the grease volume manufactured in the United States.

Details

Industrial Lubrication and Tribology, vol. 28 no. 5
Type: Research Article
ISSN: 0036-8792

Article
Publication date: 8 January 2024

Zhicai Du, Qiang He, Hengcheng Wan, Lei Zhang, Zehua Xu, Yuan Xu and Guotao Li

This paper aims to improve the tribological properties of lithium complex greases using nanoparticles to investigate the tribological behavior of single additives (nano-TiO2 or…

Abstract

Purpose

This paper aims to improve the tribological properties of lithium complex greases using nanoparticles to investigate the tribological behavior of single additives (nano-TiO2 or nano-CeO2) and composite additives (nano-TiO2–CeO2) in lithium complex greases and to analyze the mechanism of their influence using a variety of characterization tools.

Design/methodology/approach

The morphology and microstructure of the nanoparticles were characterized by scanning electron microscopy and an X-ray diffractometer. The tribological properties of different nanoparticles, as well as compounded nanoparticles as greases, were evaluated. Average friction coefficients and wear diameters were analyzed. Scanning electron microscopy and three-dimensional topography were used to analyze the surface topography of worn steel balls. The elements present on the worn steel balls’ surface were analyzed using energy-dispersive spectroscopy and X-ray photoelectron spectroscopy.

Findings

The results showed that the coefficient of friction (COF) of grease with all three nanoparticles added was low. The grease-containing composite nanoparticles exhibited a lower COF and superior anti-wear properties. The sample displayed its optimal tribological performance when the ratio of TiO2 to CeO2 was 6:4, resulting in a 30.5% reduction in the COF and a 29.2% decrease in wear spot diameter compared to the original grease. Additionally, the roughness of the worn spot surface and the maximum depth of the wear mark were significantly reduced.

Originality/value

The main innovation of this study is the first mixing of nano-TiO2 and nano-CeO2 with different sizes and properties as compound lithium grease additives to significantly enhance the anti-wear and friction reduction properties of this grease. The results of friction experiments with a single additive are used as a basis to explore the synergistic lubrication mechanism of the compounded nanoparticles. This innovative approach provides a new reference and direction for future research and development of grease additives.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-09-2023-0291/

Details

Industrial Lubrication and Tribology, vol. 76 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 December 1999

M. Alagar and V. Mohan

Different percentages of calcium and lithium stearate greases were prepared using dimethyldi‐2‐ethyl‐1‐hexoxysilane and dimethyldi‐1‐dodecoxysilane as base oils by open kettle…

Abstract

Different percentages of calcium and lithium stearate greases were prepared using dimethyldi‐2‐ethyl‐1‐hexoxysilane and dimethyldi‐1‐dodecoxysilane as base oils by open kettle process and then were characterised. The performance of different greases has been studied by determining their apparent viscosity, consistency, dropping point, oxidation stability, anti‐wear characteristics and moisture resistance. These properties are compared with those of tetra‐2‐ethyl‐1‐hexoxysilane and polydimethylsiloxane greases. Lithium stearate thickened greases exhibit better lubrication and heat resistance properties than those of calcium stearate and can be used for extreme temperature conditions in the range between –70°C and +220°C for automotive ball joints, aircrafts, antifriction, ball bearings etc.

Details

Industrial Lubrication and Tribology, vol. 51 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 4 March 2014

Maciej Paszkowski and Sylwia Olsztyńska-Janus

The thixotropy of lubricating grease thickened with lithium 12-hydroxystearate with mineral base oil was investigated. The thixotropy has a significant influence on the flow…

1845

Abstract

Purpose

The thixotropy of lubricating grease thickened with lithium 12-hydroxystearate with mineral base oil was investigated. The thixotropy has a significant influence on the flow resistance and pressure drop in the structural components of lubrication systems, which is of major importance as today the latter are being centralized and automated. The paper aims to discuss these issues.

Design/methodology/approach

Rheometer studies on thixotropy were carried out and the grease microstructure was visualized using atomic force microscopy (AFM). Total reflection Fourier transform infrared spectroscopy (ATR-FTIR) was used to study the physicochemical interactions which indicate the disintegration and recovery of the grease microstructure.

Findings

A qualitative assessment of the physicochemical interactions between lithium soap floccules was made and a theory of the self-ordering effect of lithium 12-hydroxystearate associated molecules during shearing and their aggregation and flocculation during relaxation has been proposed.

Originality/value

Because of the complexity of the disintegration and recovery of the lubricating grease thickener microstructure, there is still limited physical understanding of the mechanism of this process. Therefore, the present research was undertaken to identify the phenomena involved.

Details

Industrial Lubrication and Tribology, vol. 66 no. 2
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 14 September 2015

Juozas Padgurskas, Raimundas Rukuiža, Arturas Kupcinskas and Raimondas Kreivaitis

The purpose of this paper is to conduct research on the possibility of improving the tribological and utilization properties of lard and rapeseed oil bio-based greases by mixing…

Abstract

Purpose

The purpose of this paper is to conduct research on the possibility of improving the tribological and utilization properties of lard and rapeseed oil bio-based greases by mixing it with ethanol and selection of thickener and modification with special biological additives.

Design/methodology/approach

Rapeseed oil- and lard-based greases with sodium and lithium soap thickeners were mixed with either water or ethanol and modified with a special biological anti-wear additive. Tribological properties of modified lubricants evaluated on a four-ball machine.

Findings

Rapeseed oil- and lard-based greases suspended in ethanol and modified with bio-additive have the same wear resistance as the industrial non-biological lubrication grease and much higher wear resistance as bio-based reference grease. The tribological efficiency of the additives is higher in greases of rapeseed oil and less efficient in lard-based greases. Oxidation and wear tests show that investigated bio-based greases have comparatively stable tribological properties also after their aging. Modified greases have sufficient consistence according penetration measurements and high thermal resistance according drop-point temperature measurements. All produced experimental greases pass within the category of the easily degradable materials.

Originality/value

The greases mixed with the ethanol make possible to form more homogeneous and stable grease mixture. Modified bio-based greases have significantly higher wear resistance as bio-based reference grease, their lubrication properties are stable also after the aging and are categorized as easily degradable materials.

Details

Industrial Lubrication and Tribology, vol. 67 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 February 1995

Ryszard Czarny

Describes the structure and rheological characteristics of soap based greases and how the thickener retains the oil phase. Illustrates the thixotropic behaviour and effect of time…

446

Abstract

Describes the structure and rheological characteristics of soap based greases and how the thickener retains the oil phase. Illustrates the thixotropic behaviour and effect of time of shearing on friction, film thickness, noise energy loss in grease lubricated contacts. Shows how friction can be less with grease than with oil.

Details

Industrial Lubrication and Tribology, vol. 47 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 March 1963

S. FRED CALHOUN and GEORGE P. MURPHY

This paper is a summary of the work done at Rock Island Arsenal on additives for greases. It covers antioxidants, antiwear and extreme pressure agents and rust preventive…

Abstract

This paper is a summary of the work done at Rock Island Arsenal on additives for greases. It covers antioxidants, antiwear and extreme pressure agents and rust preventive additives. No attempt is made to list the results of all additives tested. Instead the additives are divided into groups of related compounds and the results of typical, ones given. A general evaluation of each group as a whole is given, Classes of compounds which proved good as antioxidants were metal dithiocarbamates, amino‐phenyl ethers, phenylene‐diamines, methane derivatives and certain hindered phenols and di‐substituted amines. The temperature barrier was the major obstacle for the anti‐oxidants and only 9 of the 100 or so which were effective at 21()°F, were equally effective at 250°F. Sulfur, chlorine, and lead‐containing additives were the best for extreme pressure improvement. Those containing only phosphorous were belter for antiwear. Improvements in both properties could be obtained by mixing the additives. Improvement in either property seemed to depend, more upon the type of compound than upon the responsible element. For example, all sulfur containing compounds were not equal in extreme pressure properties. Some of the antiwear and extreme pressure additives were tested for their ability to reduce fretting corrosion. Results indicate that sulfur containing compounds reduce fretting while, compounds containing only phosphorous increased it. Results are given which indicate that molybdenum disulfide added to greases is detrimental to wear at lower loadings. It does improve the extreme pressure abilities of the grease. Us presence in a grease increases the rusting tendencies of greases unless an antirust agent is also present.

Details

Industrial Lubrication and Tribology, vol. 15 no. 3
Type: Research Article
ISSN: 0036-8792

Article
Publication date: 1 March 1977

A joint paper by G. L. HARTING, of Exxon Research and Engineering Company and T. C. WILSON, Exxon Company of USA present a joint paper at the National Lubricating Grease Institute…

Abstract

A joint paper by G. L. HARTING, of Exxon Research and Engineering Company and T. C. WILSON, Exxon Company of USA present a joint paper at the National Lubricating Grease Institute annual general meeting.

Details

Industrial Lubrication and Tribology, vol. 29 no. 3
Type: Research Article
ISSN: 0036-8792

Article
Publication date: 6 August 2019

Lidan Yao, Lixin Wang, Haining Yang, Chuan Li, Hui Song and Xianguo Hu

This paper aims to investigate the influence of stearate types on the thickening ability, dropping point and fiber structure of greases.

Abstract

Purpose

This paper aims to investigate the influence of stearate types on the thickening ability, dropping point and fiber structure of greases.

Design/methodology/approach

Several greases were prepared from polyolefins and various stearates. The melting point of the stearates and the dropping point of the resultant greases were measured, and the intermolecular binding energies of the thickener and the radial distribution function of the metal–oxygen in the thickener were determined with the aid of molecular simulation. The microstructures of the greases were also analyzed via scanning electron microscopy.

Findings

A higher stearate binding energy was found to correlate to a higher dropping point of the resultant greases. The thickening ability of the stearate is related to the group and period of the constituent metal ion. Within a group, greater atomic numbers of the metal were correlated to lower thickening ability. In a period, as the atomic number of the metal increased, the thickening ability was enhanced. The radial distribution functions of metal and oxygen can explain the aggregation of the stearate thickeners in the grease.

Originality/value

This work compared the thickening capacity of several stearates. Guidelines for preparing stearates to tailor the resultant grease are presented.

Details

Industrial Lubrication and Tribology, vol. 71 no. 9
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 13 August 2018

Wenxing Niu, Lei Liu, Hong Xu and Jinxiang Dong

The purpose of this paper is to study the tribological properties of (C9H8N)4(H2O)4[Zr8P12O40(OH)8F8] (designated as ZrPOF-Q1) used as an additive in lithium grease.

137

Abstract

Purpose

The purpose of this paper is to study the tribological properties of (C9H8N)4(H2O)4[Zr8P12O40(OH)8F8] (designated as ZrPOF-Q1) used as an additive in lithium grease.

Design/methodology/approach

The tribological properties of ZrPOF-Q1 as an additive in the lithium grease were evaluated with a four-ball tester. To understand the lubrication mechanism, post-test characterization of the contact tracks was performed via three-dimensional (3D) optical profiler, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS).

Findings

The results reveal that ZrPOF-Q1 exhibits good performance in anti-wear, friction-reducing and load-carrying capacity. The action mechanism is estimated through analysis of the worn surface with SEM, EDS and 3D. The results indicate that ZrPOF-Q1 can adhere on the substrate, protecting the rubbed surfaces from a direct contact, even under high load for a long-time test. ZrPOF-Q1 can adhere on the substrate, protecting the rubbed surfaces from a direct contact, even under high load for a long-time test.

Originality/value

This work illustrates that ZrPOF-Q1 as an additive can improve lubricating performance. These tribological properties make ZrPOF-Q1 a promising candidate for lubricant additive.

Details

Industrial Lubrication and Tribology, vol. 70 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

1 – 10 of 238