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Article
Publication date: 14 June 2013

Ming Zhang, Xiaobo Wang and Weimin Liu

The purpose of this paper is to study the influences of test conditions to the tribological behavior of LaF3 nanoparticles as an additive to a polyalphaolefin (PAO).

Abstract

Purpose

The purpose of this paper is to study the influences of test conditions to the tribological behavior of LaF3 nanoparticles as an additive to a polyalphaolefin (PAO).

Design/methodology/approach

An Optimol‐SRV4 oscillating friction and wear tester (SRV) were used to investigate the tribological properties of LaF3 nanoparticles as an additive in a polyalphaolefin (PAO). The 3‐D morphologies and wear loss volume of the worn scar were measured using a surface profilometer. The chemical state and the intensity of La and F elements on worn surface after friction test was investigated with X‐ray photoelectron spectroscopy to interpret the possible mechanisms of friction‐reduction and anti‐wear with LaF3 nanoparticles.

Findings

The experimental results show that LaF3 nanoparticles added to PAO exhibit excellent load‐carrying capacity, anti‐wear and friction‐reduction properties. LaF3 nanoparticles deposited on the worn surface under lower test temperature during the friction test, and higher applied load, higher test frequency and longer test duration are propitious to the deposition of LaF3 nanoparticles accumulated on the rubbing surface. Under higher temperature, a complicated tribo‐chemical reaction occurred during the friction process, the tribo‐chemical reaction product of La2O3 deposit on worn surface, which also exhibits good lubricating performance.

Originality/value

This paper investigates the tribological properties of LaF3 nanoparticles as green oil additive in poly‐alpha‐olefin (PAO) under variable temperature, applied load, sliding speed and sliding duration. The results could be very helpful for the further applications of LaF3 nanoparticles additives in industry.

Details

Industrial Lubrication and Tribology, vol. 65 no. 4
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 21 May 2021

Suresh Ramachandra

This paper aims to document the narratives that emerged in favour of and against the austerity measures proposed by the Auckland Council, with specific reference to…

Abstract

Purpose

This paper aims to document the narratives that emerged in favour of and against the austerity measures proposed by the Auckland Council, with specific reference to performing arts organisations (PAOs) in the aftermath of the pandemic 2020.

Design/methodology/approach

Written submissions from stakeholders received in response to austerity measures were analysed to identify the arguments presented to support/oppose funding cuts to PAOs. These narratives were thematically grouped into accounting, political, artistic and social categories to deliberate on the tensions that exist between these when funding PAOs.

Findings

This study identifies the arguments presented by grass-root PAOs on the rationale of their existence from a Pacific perspective. The analysis suggests that accounting, hitherto considered as a “sword” can also be used as a “shield” if PAOs direct their research accordingly and offers future research directions.

Originality/value

Prior studies concerning funding difficulties of PAOs have relied on opinions obtained ex-post from selected stakeholders. There are no known studies, which factor the opinions of grass-root PAOs, captured “during” funding deliberations. This study bridges this gap in the New Zealand setting by providing an analysis of grass-root opinions from the Pacific perspective, conducted during a funding deliberation.

Details

Pacific Accounting Review, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0114-0582

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Article
Publication date: 10 August 2018

Yongliang Jin, Haitao Duan, Lei Wei, Song Chen, Xuzheng Qian, Dan Jia and Jian Li

This paper aims to investigate the tribological behavior and online infrared spectra of three types of lubricating oils containing dinonyl diphenylamine (DNDA…

Abstract

Purpose

This paper aims to investigate the tribological behavior and online infrared spectra of three types of lubricating oils containing dinonyl diphenylamine (DNDA) antioxidant, which are mineral oil (MO), poly alpha olefin (PAO) and trimethylolpropane trioleate (TMPTO), during the friction process at high temperature (temperature rising at first and isothermal holding afterwards).

Design/methodology/approach

A platform of low speed four-ball tribometer equipped with a temperature controller combined with infrared spectrometer was established. MO, PAO and TMPTO base oils were mixed with 1.0 Wt.% DNDA antioxidant, coded as MOa, PAOa and TMPTOa in sequence. The friction coefficient and online infrared spectra of the oils were tested during the friction process of temperature rising at first and isothermal holding afterwards, and the wear tracks of the upper balls were measured using a confocal scanning optical microscope.

Findings

The results indicated that the DNDA antioxidant was depleted to reduce the generation of alcohols and carbonyl products, and the depletion rate of DNDA followed the sequence of MOa > PAOa > TMPTOa. In the temperature rising friction process, the critical transition of friction coefficient was confirmed. The addition of DNDA antioxidant reduced the temperature of the oils at the critical transition of friction coefficient, and the temperature followed the sequence of TMPTOa > PAOa > MOa. After the critical transition, the friction coefficient was first increased and then declined to a steady value; the friction coefficient of MOa increased and declined first, followed by PAOa and TMPTOa. In the steady stage of friction, there was no obvious effect of DNDA on the friction coefficient of the oils. Moreover, DNDA enhanced the wear properties of MOa and PAOa; no obvious improvement was revealed for the wear property of TMPTOa.

Originality/value

The established platform of low speed four-ball tribometer combined with infrared spectrometer successfully realized online testing of the structure changes of lubricating oil during high temperature friction, which can give some reference on the oxidation and friction researches of lubricating oil.

Details

Industrial Lubrication and Tribology, vol. 70 no. 7
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 4 February 2014

Zhengfeng Jia, Yan-qiu Xia, Xin Shao and San-ming Du

– The purpose of this paper is to investigate the tribological properties of poly-alpha-olefin (PAO) with nano/microstructure core-shell lanthanum borate-SiO2 composites (OCLS).

Abstract

Purpose

The purpose of this paper is to investigate the tribological properties of poly-alpha-olefin (PAO) with nano/microstructure core-shell lanthanum borate-SiO2 composites (OCLS).

Design/methodology/approach

Oleic acid-capped core-shell lanthanum borate-SiO2 composites were synthesized by an easy way. The composites were characterized by means of Fourier transform-infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and thermo gravimetric analysis (TGA). The friction and wear behaviors of the quenched AISI 1045 steel specimens sliding against AISI 52100 steel under the lubrication of PAO containing OCLS were comparatively investigated with PAO containing SiO2 additive on an Optimol SRV reciprocating friction and wear tester. On the other hand, the tribological properties of the PAO containing OCLS were also investigated on four-ball tester.

Findings

The diameter of OCLS was about 20 nm, and the thickness of the SiO2 shell was less than 5 nm. The ratio of oleic acid (OA) is about 15 percent. The PAO containing OCLS possesses much better tribological properties than that of pure PAO and PAO containing SiO2 additive.

Originality/value

The PAO+OCLS possess a better friction reducing and antiwear properties than pure PAO. The new additive can improve the tribological ability of machinery.

Details

Industrial Lubrication and Tribology, vol. 66 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 8 February 2016

Weiwei Wang, Shan Jiang, Yan Shen, Shunba Xia and Jiujun Xu

This paper aims to address the polymerization of 1-decene by [Emim]Cl/AlCl3 ionic liquid and the film-forming properties of the product compared with commercially…

Abstract

Purpose

This paper aims to address the polymerization of 1-decene by [Emim]Cl/AlCl3 ionic liquid and the film-forming properties of the product compared with commercially available base stocks.

Design/methodology/approach

Experiments were carried out to investigate the influence of [Emim]Cl/AlCl3 mole ratio, catalyst dosage, reaction temperature, reaction time and water on the polyreaction. Poly alpha-olefin (PAO) is prepared under optimal reaction condition. Film-forming properties of PAO have been compared with those of Group I, Group II and Group III base stocks, which are selected with approximately the same viscosity.

Findings

Experimental results show that after a 4-h reaction time, yield of PAO can be higher than 85 per cent and viscosity index can be up to 160 with [Emim] Cl/AlCl3 mole ratio of 2:1, catalyst dosage of 3 per cent wt. and water content of 20 ppm. A strong influence of water on reaction is observed. With approximately the same viscosity, PAO shows the superiority in film thickness at low-sliding speeds compared with Group I and Group II base stocks. At high temperature, PAO provides a thicker film than other base stocks.

Originality/value

In recent years, there has been considerable interest in ionic liquids. As a novel catalyst, it has so many advantages including low corrosion, low toxicity, low cost and a potentially wide range of properties compared with traditional catalysts. This paper reports the polymerization of 1-decene by [Emim]Cl/AlCl3 ionic liquid and the study on lubricating properties of PAO compared with mineral base stocks.

Details

Industrial Lubrication and Tribology, vol. 68 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 9 March 2010

Yubin Sun, Litian Hu and Qunji Xue

The purpose of this paper is to investigate the hydrolytic stability of several S‐hydroxyethyl N,N‐dialkyl dithiocarbamate‐derived borates SNB1, SNB2, and SNB3, to…

Abstract

Purpose

The purpose of this paper is to investigate the hydrolytic stability of several S‐hydroxyethyl N,N‐dialkyl dithiocarbamate‐derived borates SNB1, SNB2, and SNB3, to evaluate their tribological performances used as additives in polyalpha olefins (PAO), and to explore the tribochemical action mechanism.

Design/methodology/approach

First, the three additives are synthesized and characterized. Second, the hydrolytic stabilities of the three compounds are investigated. As the third step, they are, respectively, added to PAO and a series of samples with different concentrations of the additives in PAO are prepared, respectively. Their tribological properties are evaluated with two types of four‐ball machines, and then the wear scars were observed using a JSM‐5600LV scanning electron microscope. Finally, the elements on the worn surface are analyzed with a X‐ray photoelectron spectroscope (XPS).

Findings

The three novel compounds possess relatively good hydrolytic stabilities, excellent anti‐wear (AW) performances, friction reduction properties, and load‐carrying capacity. There is an optimum concentration of each of the three additives for their AW properties. According to the XPS analytical results, a boundary lubrication protective film has formed during friction consisting of FeSO4 film, Fe2O3 film, and the complicated adsorption film composed of N‐containing organic compounds. In the protective films, a large quantity of compounds containing element B is not found.

Research limitations/implications

The antioxidation performances and the anticorrosion properties are not estimated.

Practical implications

Three novel AW/extreme pressure (EP) additives are synthesized, and may be they have the potential industrial application as AW/EP additives in lubricating oil.

Originality/value

The present work provides a research method of N,S‐containing organic borates as lubricating oil additives.

Details

Industrial Lubrication and Tribology, vol. 62 no. 2
Type: Research Article
ISSN: 0036-8792

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Abstract

Purpose

There is a continuous drive in automotive sector to shift from conventional lubricants to environmental friendly ones without adversely affecting critical tribological performance parameters. Because of their favorable tribological properties, chemically modified vegetable oils such as palm trimethylolpropane ester (TMP) are one of the potential candidates for the said role. To prove the suitability of TMP for applications involving boundary-lubrication regime such as cam/tappet interface of direct acting valve train system, a logical step forward is to investigate their compatibility with conventional lubricant additives.

Design/methodology/approach

In this study, extreme pressure and tribological characteristics of TMP, formulated with glycerol mono-oleate (GMO), molybdenum dithiocarbamate (MoDTC) and zinc dialkyldithiophosphate (ZDDP), has been investigated using four-ball wear tester and valve train test rig. For comparison, additive-free and formulated versions of polyalphaolefin (PAO) were used as reference. Moreover, various surface characterization techniques were deployed to investigate mechanisms responsible for a particular tribological behavior.

Findings

In additive-free form, TMP demonstrated better extreme pressure characteristics compared to PAO and lubricant additives which are actually optimized for conventional base-oils such as PAO, are also proved to be compatible with TMP to some extent, especially ZDDP. During cylinder head tests, additive-free TMP proved to be more effective compared to PAO in reducing friction of cam/tappet interface, but opposite behavior was seen when formulated lubricants were used. Therefore, there is a need to synthesize specialized friction modifiers, anti-wear and extreme pressure additives for TMP before using it as engine lubricant base-oil.

Originality/value

In this study, additive-free and formulated versions of bio-lubricant are tested for cam/tappet interface of direct acting valve train system of commercial passenger car diesel engine for the very test time. Another important aspect of this research was comparison of important tribological performance parameters (friction torque, wear, rotational speed of tappet) of TMP-based lubricants with conventional lubricant base oil, that is, PAO and its formulated version.

Details

Industrial Lubrication and Tribology, vol. 70 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 9 March 2015

Martin Greaves and Ksenija Topolovec Miklozic

The purpose of this paper was to examine the film-forming behaviour of simple compositions of polyalphaolefin (PAO) containing an oil-soluble polyalkylene glycol (OSP…

Abstract

Purpose

The purpose of this paper was to examine the film-forming behaviour of simple compositions of polyalphaolefin (PAO) containing an oil-soluble polyalkylene glycol (OSP) alone, a zinc dialkyl dithiophosphate (ZDDP) alone and then combinations of an OSP and ZDDP.

Design/methodology/approach

A Mini-Traction Machine with Spacer Layer Imaging technology was used to evaluate friction and film formation under a specific contact pressure, temperature and slide-to-roll ratio. Electrical contact resistance measurements were used to follow surface film formation.

Findings

The inclusion of an OSP to a PAO showed evidence of friction-reducing behaviour with low friction values over the rubbing cycle but no significant tribo-film build up. When a ZDDP (1 per cent) is added to the PAO, a thick tribo-film forms of about 100 nm. Addition of an OSP (10 per cent) shows this film still forms despite the OSP being a polar and surface-active additive.

Research limitations/implications

The study was conducted under a narrow range of test conditions (e.g. temperature and contact pressure), and future work will focus on friction and film formation across a broader set of conditions.

Practical implications

Despite OSPs being polar and surface-active, they do not interfere with the ZDDP in forming an anti-wear film in a PAO and, therefore, their inherent properties of good deposit control could enhance the performance of modern lubricants.

Originality/value

OSPs offer promising benefits as friction reducers in PAOs. The research also suggests that OSPs do not negate the formation of ZDDP anti-wear tribo-films when in combination in a PAO.

Details

Industrial Lubrication and Tribology, vol. 67 no. 2
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 11 September 2007

Luciano Barin Cruz, Eugenio Avila Pedrozo, Rosangela Bacima and Beatriz Queiroz

Inspired by a framework about the insertion of sustainable development in business strategy proposed by Steurer et al., the purpose of this article is to describe the…

Abstract

Purpose

Inspired by a framework about the insertion of sustainable development in business strategy proposed by Steurer et al., the purpose of this article is to describe the Caras do Brasil (Faces of Brazil) program, highlighting its characteristics and how these can contribute to a new interpretation of the framework initially proposed.

Design/methodology/approach

A posteriori longitudinal research was undertaken with the first phase containing the theoretical research and the second phase containing the study of the Caras do Brasil (Faces of Brazil) program, which was designed as an incentive for the commercial development of small producers.

Findings

The present case demonstrates two characteristics that give reason to refine the framework proposed by Steurer et al. stakeholder pressures (either transactional or interactional) present differently; and the pressure of stakeholders is predominantly related to social concerns, rather than the predominance of environmental concerns stated by Steurer et al.

Research limitations/implications

The study limited itself to a posteriori data collection of the presented case, given that it was impossible to follow the program regularly from its implementation. The results were generated through the perspectives of employees in the sustainable development department of the Pão de Açucar Group, in view of the fact that it was not possible to interview each of the stakeholders involved.

Practical implications

For managers of many companies, the case can be considered an example of programs that seek to develop commercial activities with producers of poorer regions through the equilibrium of the economic, social and environmental dimensions.

Originality/value

The article demonstrates the differences of interpretation of the framework proposed by Steurer et al. when it is used to analyze a business program in a southern country such as Brazil. Separating transactional and interactional stakeholders grants the framework a higher level of detail.

Details

Management Decision, vol. 45 no. 8
Type: Research Article
ISSN: 0025-1747

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Article
Publication date: 9 April 2018

Bin Shi, Jian Hua Guo, Xing An Cao, En Zhu Hu and Kun Hong Hu

This paper aims to explore the effects of mineral diesel fuel carbon soot (MCS) and biodiesel carbon soot (BCS) on the lubrication of polyalphaolefin (PAO) and diesel fuels.

Abstract

Purpose

This paper aims to explore the effects of mineral diesel fuel carbon soot (MCS) and biodiesel carbon soot (BCS) on the lubrication of polyalphaolefin (PAO) and diesel fuels.

Design/methodology/approach

Two styles of carbon soot were prepared from the natural combustion of mineral diesel fuel oil (MDO) and biodiesel oil (BDO). Tribological tests were conducted on a high-frequency reciprocating rig. Friction surfaces were characterized using three-dimensional laser scanning confocal microscopy and Raman spectroscopy.

Findings

The addition of MCS and BCS to PAO could reduce friction in most cases. MCS had a negligible effect on the wear for contents not exceeding 1.0 per cent. By contrast, BCS exhibited a considerable negative influence on the wear resistance even at low contents. For diesel fuels, MCS reduced both friction and wear, whereas BCS substantially deteriorated the lubrication of BDO. MCS formed a Fe3O4/C composite lubricating film on the friction surface. BCS also entered the contact region, but it did not form an effective Fe3O4/C composite lubricating film.

Originality/value

This work compared MDO and BDO from a different perspective, i.e. the effects of their combustion carbon soot on the lubrication of lubricating oil and fuel oil. The significant negative effect of BCS on the lubrication of lubricating oil and BDO is a problem that could occur in the industrial application of BDO.

Details

Industrial Lubrication and Tribology, vol. 70 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

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