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Article
Publication date: 1 August 2002

L. Rapoport, V. Leshchinsky, M. Lvovsky, O. Nepomnyashchy, Yu Volovik and R. Tenne

In the past few years, inorganic fullerene‐like (IF) supramolecules of metal dichalcogenide WS2 and MoS2 with structures closely related to (nested) carbon fullerenes and…

1131

Abstract

In the past few years, inorganic fullerene‐like (IF) supramolecules of metal dichalcogenide WS2 and MoS2 with structures closely related to (nested) carbon fullerenes and nanotubes have been synthesized. Recent experiments showed that IF added to oil and impregnated into the porous matrixes possess lubricating properties superior to those of layered WS2 and MoS2 (2H platelets). The main goal of this work was to analyze the mechanism of friction of fullerene‐like nanoparticles. Friction and wear behavior of IF in different contact conditions is studied. Third body model is considered. Sliding/rolling of the IF nanoparticles in the boundary of the first bodies and in between the wear particles (third body) is supposed to facilitate the shear of the lubrication film. Broken and oxidized 2H‐WS2 small pieces adhered to wear debris do not provide high tribological properties especially under high loads.

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Industrial Lubrication and Tribology, vol. 54 no. 4
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 2 May 2008

Xiaodong Zhou, Huaqiang Shi, Xun Fu, Danmei Wu and Zhengshui Hu

The purpose of this paper is to investigate the tribological properties of MoS2 nano‐sized hollow spheres in liquid paraffin (LP) and the corresponding action mechanism. Morever…

745

Abstract

Purpose

The purpose of this paper is to investigate the tribological properties of MoS2 nano‐sized hollow spheres in liquid paraffin (LP) and the corresponding action mechanism. Morever, its feasibity of industrial application as an oil additive in the industrial lubrication field is also explored.

Design/methodology/approach

The tribological properties of MoS2 nano‐sized hollow spheres (NH‐MoS2) modified by Cyanex 301(di‐(2,4,4‐trimethylpentyl) dithiophosphinic acid) with size of 200 ∼ 300 nm in LP are studied and compared with those of the commercial colloidal MoS2 (CC‐MoS2) on a four‐ball tester and an Optimol SRV Oscillating friction and wear tester in a ball‐on disk configuration. The worn surfaces of the lower flat disc are examined with a scanning electron microscopy and an X‐ray photoelectron spectroscopy, respectively.

Findings

Results show that NH‐MoS2 is a better extreme‐pressure additive and anti‐wear (AW) and friction‐reducing additive in LP than CC‐MoS2. Under the optimum concentration of 0.5 per cent for both NH‐MoS2 and CC‐MoS2 and the load of 400 N, the friction coefficient of NH‐MoS2 + LP and CC‐MoS2 + LP decreases about 43.8 and 6.3 per cent, and the wear volume loss decreases about 60.3 and 12.0 per cent compared with the pure LP. The boundary lubrication mechanism for NH‐MoS2 + LP can be deduced as the effective chemical adsorption protective film formed by the long chain alkyls R and active elements (S and P) in the modification layer and tribochemical reaction film containing the tribochemical products of the additive. Moreover, sliding and rolling frictions co‐exist in NH‐MoS2 + LP, doing contributions to the good tribological properties as well.

Originality/value

In this paper, the Cyanex 301‐modified MoS2 nano‐sized hollow spheres with diameter of 200 ∼ 300 nm are firstly added into LP to investigate its tribological properties. The excellent AW and friction‐reducing properties indicate that this MoS2 hollow spheres product is a good oil additive, and the fundamental data presented here will be useful for its further industrial application in the future.

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Industrial Lubrication and Tribology, vol. 60 no. 3
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 12 September 2016

Gustavo Tontini, Guilherme Dalla Lana Semione, Cristian Bernardi, Roberto Binder, José Daniel Biasoli de Mello and Valderes Drago

This paper aims to synthesize nanostructured flower-like molybdenum disulphide (MoS2) particles and evaluate their suitability to act as additives for lubricants.

458

Abstract

Purpose

This paper aims to synthesize nanostructured flower-like molybdenum disulphide (MoS2) particles and evaluate their suitability to act as additives for lubricants.

Design/methodology/approach

A hydrothermal method without any surfactant successfully produced 250 nm mean diameter Nanostructured flower-like MoS2 particles. The resulting product was then solvothermally treated with absolute ethanol producing lipophilic powder particles which after being dispersed in two different lubricants were tribologicaly characterized by using a pin-on-disk tribometer geometry with reciprocal movement under immersion.

Findings

The influence on the stability and the coefficient of friction of the nano-oils is shown to be strongly dependent on their molecular structure. After 1 h of tribological testing, a ramified polyolester oil with 1 Wt.% of MoS2 nanoflowers did not show decrease in its average coefficient of friction, while an additive naphthenic oil with the same concentration of nanoparticles showed a decrease of 86 per cent.

Originality/value

In this paper, nanostructured flower-like MoS2 synthesized by the hydrothermal method was dispersed in lubricating oils to study its stability and tribological properties. To ensure good stability of the nano-oils, the particles were solvothermally treated with absolute ethanol to dehydrate and lipophilize them. A ramified polyolester-based nano-oil with 1 Wt.% of MoS2 nanoflowers showed no decrease in its steady state coefficient of friction, while a naphthenic-based nano-oil with the same concentration of nanoparticles presented a remarkable 86 per cent reduction.

Details

Industrial Lubrication and Tribology, vol. 68 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 12 March 2018

Maheswaran R. and Sunil J.

The optimal performance of the machinery is based on lubricants that require frequent monitoring and the analysis of characteristics such as chemical content, contamination and…

129

Abstract

Purpose

The optimal performance of the machinery is based on lubricants that require frequent monitoring and the analysis of characteristics such as chemical content, contamination and viscosity. The application of nanoparticles dispersed lubricant in tribology has received remarkable attention in recent years. This paper aims to investigate the tribological properties of SN500 grade lubricating oil containing garnet nanoparticles.

Design/methodology/approach

In this study, 45-nm-sized garnet particles are ultrasonically dispersed in SN500 grade base lubricant oil. The effects of viscosity and additive concentration on tribological properties are investigated using a four-ball tester.

Findings

Rolling, reinforcing and film-forming behaviour of dispersed nano-sized garnet additives in the rubbing zone were investigated using scanning electron microscopy equipped with energy dispersive spectroscopy. The results indicate that the garnet additives can improve the wear resistance and resistance to relative motion and decrease the friction coefficient of rubbing steel interface by surface polishing and formation of tribo-film containing Si, C and Mn.

Originality/value

Because of the complex two-phase solid–liquid mixture, there are still limited physical understandings of the friction and wear reduction mechanisms. Therefore, the present research was undertaken to interpret the possible phenomena.

Details

Industrial Lubrication and Tribology, vol. 70 no. 2
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 27 September 2011

Yuh‐Yih Wu and Mu‐Jung Kao

Nanoparticles have been studied as additives to lubrication oils for reducing friction and wear. The purpose of this paper is to investigate the effect of nanofluid on engine oil…

6222

Abstract

Purpose

Nanoparticles have been studied as additives to lubrication oils for reducing friction and wear. The purpose of this paper is to investigate the effect of nanofluid on engine oil and friction reduction in a real engine.

Design/methodology/approach

The nanoparticles were prepared using a high‐temperature arc in a vacuum chamber to vaporize the Ti metal, and then condensed into a dispersant to form the TiO2 nanofluid, which was used as lubricant additive. Experiments were performed in both real engine running and test rig.

Findings

It was found that the engine oil with nanofluid additive with an ethylene glycol dispersant of nanoparticles, had gelled after 10‐h of engine running. The problem of oil gelation (jelly‐like) was solved by replacing the dispersant with paraffin oil. The engine oil with TiO2 nanoparticle additive exhibited lower friction force as compared to the original oil. The experiment showed that a smaller particle size exhibits better friction reduction with particle size ranging from 59 to 220 nm.

Research limitations/implications

The paper is restricted to findings based on the dispersed nanoparticles in fluid as additive for engine lubrication oil.

Practical implications

The test results are useful for the application of nanofluid additive for engine oil.

Originality/value

Most previous researches in this field were executed on tribotester, rather than the actual engine. This paper describes experimental methods and equipment designed to investigate the application of TiO2 nanofluid as lubricant additive in internal combustion engine.

Details

Industrial Lubrication and Tribology, vol. 63 no. 6
Type: Research Article
ISSN: 0036-8792

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Book part
Publication date: 21 November 2016

Mattie Tops, Jesús Montero-Marín and Markus Quirin

Engagement, motivation, and persistence are usually associated with positive outcomes. However, too much of it can overtax our psychophysiological system and put it at risk. On…

Abstract

Engagement, motivation, and persistence are usually associated with positive outcomes. However, too much of it can overtax our psychophysiological system and put it at risk. On the basis of a neuro-dynamic personality and self-regulation model, we explain the neurobehavioral mechanisms presumably underlying engagement and how engagement, when overtaxing the individual, becomes automatically inhibited for reasons of protection. We explain how different intensities and patterns of engagement may relate to personality traits such as Self-directedness, Conscientiousness, Drive for Reward, and Absorption, which we conceive of as functions or strategies of adaptive neurobehavioral systems. We describe how protective inhibitions and personality traits contribute to phenomena such as disengagement and increased effort-sense in chronic fatigue conditions, which often affect professions involving high socio-emotional interactions. By doing so we adduce evidence on hemispheric asymmetry of motivation, neuromodulation by dopamine, self-determination, task engagement, and physiological disengagement. Not least, we discuss educational implications of our model.

Details

Recent Developments in Neuroscience Research on Human Motivation
Type: Book
ISBN: 978-1-78635-474-7

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Article
Publication date: 4 September 2017

Carmen Torres-Sanchez and Nikolaos Balodimos

The purpose of this paper is to propose a nanodiamond-particle-loaded food-grade lubricating oil, a nanolubricant, that can be used over a broad range of loads in factories (low…

169

Abstract

Purpose

The purpose of this paper is to propose a nanodiamond-particle-loaded food-grade lubricating oil, a nanolubricant, that can be used over a broad range of loads in factories (low load applications like conveyor systems and high load applications like heavy machinery).

Design/methodology/approach

Tribological performance of the nanolubricant was studied at both load levels. A typical factory-sized conveyor belt used for beverage packaging (aluminium cans, glass and PET bottles) was employed for the low load range. Coefficients of friction and wear scars were measured and the lubricating performance was quantified. A four-ball tester was used to characterise the performance of the nanolubricant as per ASTM D2783/D4172. A comparison between the nanolubricant and baseline oils was carried out.

Findings

Results show an overall decrease in the coefficients of friction and wear scars for all packages at low pressures when the nanolubricant is used. They also show a better friction-reduction performance in the high load regimes. The results indicate that the nanolubricant is versatile in both ranges of loading.

Practical implications

The current protocols for lubrication in the food and drink factories involve the use of water-based detergents for the conveyor lines and industry-grade oils for the machinery. The use of a single and versatile lubricant for both ranges of loads may have a positive impact on the sustainability and environmental performance of the sector.

Originality/value

Beverage processing and packing factories need their mechanised conveyor systems suitably lubricated to avoid excessive friction between the containers and the load-bearing surface of the conveyors (e.g. belts or chains). Other areas of the conveying systems, such as motors, gears, rollers and bearings, also need suitable lubrication to prevent failure and lengthen their operating life. There is a myriad of lubricants and lubricating solutions for each of these areas independently, but there is no commercial lubricating fluid that could be used on both successfully.

Details

Industrial Lubrication and Tribology, vol. 69 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 April 1982

Ruth Tenne

In recent years the Manpower Services Commission (MSC), through its Training Services Division (TSD), has considerably extended its training operations for clerical and commercial…

22

Abstract

In recent years the Manpower Services Commission (MSC), through its Training Services Division (TSD), has considerably extended its training operations for clerical and commercial staff. The rapid growth of office technology and its increasing impact on office functions and office skills led TSD to recognise this field as one of the major priority areas of its operating plan for the years 1980–81. As a result a project was launched aiming to:

Details

Journal of European Industrial Training, vol. 6 no. 4
Type: Research Article
ISSN: 0309-0590

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Article
Publication date: 13 April 2015

Zhiru Yang, Dongfeng Diao, Hongyan Fan, Xue Fan and Chao Wang

– The purpose of this paper is to study the load capacity of nanoparticles-laden gas film (NLGF) in thrust bearing.

203

Abstract

Purpose

The purpose of this paper is to study the load capacity of nanoparticles-laden gas film (NLGF) in thrust bearing.

Design/methodology/approach

SiO2 nanoparticles were added into gas to form an NLGF. The nanoparticles volume fraction in the film was controlled by a vibrator. The film thickness and the film pressure were measured by a micro cantilever displacement sensor and a membrane pressure sensor, respectively. The total load that makes the film thickness keeping constant was quantified, and then, the film load capacity was obtained.

Findings

The investigation shows that nanoparticles can enlarge the film load capacity remarkably; even a little amount of nanoparticles (0.01 per cent) could lead to a sharp rise. With the increase of nanoparticles volume fraction, load capacity increases. However, the increment of load capacity decreases gradually. In addition, the film pressure variation proves the enhancement effect of nanoparticles on the film load capacity.

Research limitations/implications

The paper is restricted to the findings based on NLGF, which is formed by dispersing SiO2 nanoparticles in gas film as an additive. The experimental results are applicable within the range of nanoparticles volume fraction of 0.01-0.33 per cent.

Originality/value

The fact that nanoparticles could enlarge the gas film load capacity is verified by experiment for the first time. This study reveals the corresponding relation between nanoparticles volume fraction and the film load capacity.

Details

Industrial Lubrication and Tribology, vol. 67 no. 3
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 8 June 2015

Tatjana Maliar, Satish Achanta, Henrikas Cesiulis and Dirk Drees

The purpose of this paper is to investigate the tribological behaviour of commercially available SAE 10 mineral and rapeseed oils containing Fe particles synthesized directly in…

238

Abstract

Purpose

The purpose of this paper is to investigate the tribological behaviour of commercially available SAE 10 mineral and rapeseed oils containing Fe particles synthesized directly in the oil phase.

Design/methodology/approach

Sub-micron Fe particles (50-340 nm) were synthesized by wet chemical reduction reaction of FeSO4 by sodium borohydride in the rapeseed and mineral oils in the presence of surfactant: block copolymer (ENB 90R4) or oxyethylated alcohol (OS-20). A four-ball wear tribometer was used to investigate the tribological properties of mineral and rapeseed oil: coefficient of friction (COF), wear scar diameter and wear loss. Viscosity measurements of oil solutions and determination of synthesized Fe particles size were performed as well.

Findings

The presence of Fe particles (0.1 weight per cent) in the rapeseed and mineral oils caused the little change in the COF but resulted in marked improvement of anti-wear property. The oils containing Fe particles with slightly higher viscosity are giving more friction due to viscous drag. The anti-wear enhancement is attributed to the formation of tribofilm and superior load-bearing capability of the modified oil. Both rapeseed and mineral oils irrespective of used surfactant in the presence of 0.1 weight per cent Fe particles (50-140 nm) show sufficiently improved anti-wear properties.

Originality/value

The data collection about tribological behaviour of oils containing Fe particles and various additives in lubricants has a practical interest. The findings could be helpful to increase the knowledge of the behaviour of real tribological systems, where the metallic debris are generated during friction and contaminate the lubricating oil.

Details

Industrial Lubrication and Tribology, vol. 67 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

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