X‐ray absorption near‐edge structure analysis of tribofilms generated by highly efficient, friction‐reducing additive in water–polyglycol–glycol lubricant

Modern hydraulic oils have to fulfill a broad variety of parameters limitations to guarantee a proper system performance throughout a considerable lifetime. A comprehensive test of the liquids nowadays just can be performed by using long term hydraulic pump test set ups, including several different test stages. One of the most critical parameters in hydraulic pump testing is the pump wear indicating the anti-wear performance of the used oil. In this paper the authors focused on the development of a new testing procedure based on a simple standardized Brugger test aiming to achieve similar wear results as in a Parker Denison T6H20C pump test set up. The test conditions of a standard Brugger test are changed by taking a brass cylinder, reducing the normal load to 1 kg, increasing the test duration to 300 seconds, providing a well-defined surface roughness by using a 2,500 x grinding paper and perform 4 repetition tests to obtain a statistical more reliable measurement value. By using the new method it was possible to get a pre selection between pass and fail oils according to the wear properties without the necessity of performing an elaborated pump test. The preselection of hydraulic oils according to their anti-wear properties offers a huge cost saving potential for hydraulic oil developments.

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“…Furthermore it has to be done at a wide range of loads and speed. [9][10][11][12][13][14][15]. They all provide interesting results of e.g.…”

Section: State Of the Artmentioning

confidence: 86%

Simulation of Anti Wear Performance Using a Modified Brugger Test Set Up

Sequard-Base¹,

Grafl²,

Cihak-Bayr³

2018

Tribol. Ind.

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“…When changing the concentration of the additive into 1 weight per cent serpentine/5-CST, the main compounds change to more additive, magnesium oxide and magnesium silicate. According to these results with tribological data, the conclusion can be drawn that the tribofilms are composed of magnesium oxide (Jin et al, 2004;Ma et al, 2009aMa et al, , 2009bZhang et al, 2005) and magnesium sulphate, and a suitable ratio of the mixtures of magnesium oxide and magnesium sulphate in the tribofilms will obtain better anti-wear and friction-reducing performances than a single component (Trcera et al, 2007). The Mg K-edge XANES (FY) spectra of tribofilms generated from different time in the presence of 5.0 weight per cent superfine surface-coated serpentine particles in 5-CST are shown in Figure 10.…”

Section: Xanes Analysis On the Worn Surfacementioning

confidence: 92%

“…The XPS spectra of Si, Mg and O elements in tribofilms generated from different additives in the base oil are shown in Figure 8. The XPS analysis on the worn surface lubricated by the oil containing different concentrations of serpentine under 150 N for different duration was performed as referenced to that of the base oil (Li et al, 1996;Najman et al, 2004;Chen et al, 2007;Ma et al, 2009aMa et al, , 2009b. The peak fitting spectra of the typical elements such as Mg, Si and O are shown in Figure 8, and some peak positions are shown in Table III.…”

Section: Xps Analysis On the Worn Surfacementioning

confidence: 99%

Tribological behaviours of surface-modified serpentine powder as lubricant additive

Zhang

Yan

et al. 2016

Industrial Lubrication and Tribology

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Purpose – The aim of this paper is to study the tribological performance and self-repairing performance of surface-modified nanoscale serpentine powders as lubricant additives in the mineral base oil (5-CST). Design/methodology/approach – Fourier transform infrared spectroscopy spectra and thermo-gravimetric analysis of both modified and unmodified serpentine were performed to analyse their grafting ratio and suspension after modified using a long-chain naphthene aliphatic acid. The tribological properties of surface-modified serpentine as lubricant additives in 5-CST were evaluated and the worn surfaces were investigated by X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES). Findings – The results show that the serpentine particles have high grafting ratio, improving the dispersity in 5-CST. When the serpentine concentration of 1.00 weight per cent is used as additives in 5-CST, friction coefficient reduces by 14.80 per cent under 294 N and wear scar diameter (WSD) decreases by 11.82 per cent. The results of X-ray absorption near edge structure and XANES show that the adsorption and tribochemical reactions occur to form self-repairing lubrication films. Originality/value – The paper illustrates a tribofilm form on the rubbed surface, which is responsible for the decrease in friction and wear, mainly containing iron oxides, silicon oxides, magnesium oxides and organic compounds. The results are useful for further applications in advanced environmental friendly lubricating oils and additives.

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“…These additives cannot resolve in water directly, but they can be added in water by the emulsion process. Frequently used emulsifiers are non-ionic surfactants (Cambiella et al, 2006;Ma et al, 2009b). Polysorbate 80 is a non-ionic surfactant and emulsifier derived from polyethoxylated sorbitan and oleic acid which contain longer chains in the structure (Anand et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

The tribochemical study of novel phosphorous-nitrogen (P-N) type phosphoramidate additives in water

Yan

Bai

Li³

et al. 2014

Industrial Lubrication and Tribology

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Purpose -The purpose of this paper is to investigate the tribological properties of novel phosphorous-nitrogen (P-N) type additives in water. Design/methodology/approach -The tribological properties of the novel P-N additives in water are compared with a commercial lubricant additive of the P-N type using a four-ball machine. The tribological mechanism was investigated by X-ray absorption near-edge structure (XANES) spectroscopy. Findings -The experimental results indicate that the phosphoramidate derivatives possess good anti-wear and friction-reducing properties. The XANES analysis shows that the prepared compounds can form a protective film containing phosphate and/or polyphosphate that affects the tribological behavior. Originality/value -The purpose of this paper is to investigate the tribological properties of the novel P-N type additives in water.

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X‐ray absorption near‐edge structure analysis of tribofilms generated by highly efficient, friction‐reducing additive in water–polyglycol–glycol lubricant

Cited by 5 publications

References 20 publications

Simulation of Anti Wear Performance Using a Modified Brugger Test Set Up

Simulation of Anti Wear Performance Using a Modified Brugger Test Set Up

Tribological behaviours of surface-modified serpentine powder as lubricant additive

The tribochemical study of novel phosphorous-nitrogen (P-N) type phosphoramidate additives in water

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