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Article
Publication date: 9 April 2018

Carsten Gachot

523

Abstract

Details

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

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Article
Publication date: 12 June 2019

Philipp G. Grützmacher, Andreas Rosenkranz, Adam Szurdak, Markus Grüber, Carsten Gachot, Gerhard Hirt and Frank Mücklich

The paper aims to investigate the possibilities to control friction in lubricated systems by surface patterning, making use of a multi-scale approach. Surface patterns inside the…

366

Abstract

Purpose

The paper aims to investigate the possibilities to control friction in lubricated systems by surface patterning, making use of a multi-scale approach. Surface patterns inside the tribological contact zone tend to directly reduce friction, whereas surface patterns located in the close proximity of the contact area can improve the tribological performance by avoiding lubricant starvation and migration. Finally, optimized surface patterns were identified by preliminary laboratory tests and transferred to a journal bearing, thus testing them under more realistic conditions.

Design/methodology/approach

Surface patterns on a large scale (depth > 10 µm) were fabricated by micro- and roller-coining, whereas surface patterns on a small scale (depth < 2 µm) were produced by direct laser interference patterning. The combination of both techniques resulted in multi-scale surface patterns. Tribologically beneficial surface patterns (verified in ball-on-disk laboratory tests) were transferred onto a journal bearing’s shaft and tested on a special test-rig. To characterize the lubricant spreading behavior, a new test-rig was designed, which allowed for the study of the lubricant’s motion on patterned surfaces under the influence of a precisely controlled temperature gradient.

Findings

All tested patterns accounted for a pronounced friction reduction and/or an increase in oil film lifetime. The results from the preliminary laboratory tests matched well, with results from the journal bearing test-rig, both tests showing a maximum friction reduction by a factor of 3-4. Numerical investigations, as well as experiments, have shown the possibility to actively guide lubricant over patterned surfaces. Smaller periodicities, as well as greater structural depths and widths, led to a more pronounced anisotropic spreading and/or greater spreading velocities. Multi-scale surfaces demonstrated the strongest effects regarding the lubricant’s spreading behavior.

Originality/value

Friction, as well as lubricant migration, can be successfully controlled by using micro-coined, laser-patterned and/or multi-scale surfaces. To the best of the authors’ knowledge, the study demonstrates for the first time the unique possibility to transfer results obtained in laboratory tests to a real machine component.

Details

Industrial Lubrication and Tribology, vol. 71 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

Available. Open Access. Open Access
Article
Publication date: 16 April 2020

Chia-Jui Hsu, Jenifer Barrirero, Rolf Merz, Andreas Stratmann, Hisham Aboulfadl, Georg Jacobs, Michael Kopnarski, Frank Mücklich and Carsten Gachot

To decrease wear and friction, zinc dialkyldithiophosphate (ZDDP) has been used in engine oil for several decades, but the mechanism of the tribofilm formation is still unclear…

1844

Abstract

Purpose

To decrease wear and friction, zinc dialkyldithiophosphate (ZDDP) has been used in engine oil for several decades, but the mechanism of the tribofilm formation is still unclear. The purpose of this study is to characterize the chemical details of the tribofilm by using high-resolution approaching.

Design/methodology/approach

An ISO VG 100 mineral oil mixed with ZDDP was used in sliding tests on cylindrical roller bearings. Tribofilm formation was observed after 2 h of the sliding test. X-ray photoelectron spectroscopy (XPS) and atom probe tomography (APT) were used for chemical analysis of the tribofilm.

Findings

The results show that the ZDDP tribofilm consists of the common ZDDP elements along with iron oxides. A considerable amount of zinc and a small amount of sulfur were observed. In particular, an oxide interlayer with sulfur enrichment was revealed by APT between the tribofilm and the steel substrate. The depth profile of the chemical composition was obtained, and a tribofilm of approximately 40 nm thickness was identified by XPS.

Originality/value

A sulfur enrichment at the interface is observed by APT, which is beneath an oxygen enrichment. The clear evidence of the S interlayer confirms the hard and soft acids and bases principle.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0035/

Details

Industrial Lubrication and Tribology, vol. 72 no. 7
Type: Research Article
ISSN: 0036-8792

Keywords

Available. Open Access. Open Access
Article
Publication date: 16 August 2023

Florian Ausserer, Igor Velkavrh, Fevzi Kafexhiu and Carsten Gachot

This study aims to focus on the development of an experimental setup for testing tribological pairings under a gas atmosphere at pressures up to 10 bar.

186

Abstract

Purpose

This study aims to focus on the development of an experimental setup for testing tribological pairings under a gas atmosphere at pressures up to 10 bar.

Design/methodology/approach

A pressure chamber allowing oscillating movement through an outer shaft was constructed and mounted on an oscillating tribometer. Due to a metal spring bellows system, a methodology for the evaluation of the coefficient of friction values separately from the spring forces was developed.

Findings

The selected material concept was qualitatively and quantitatively assessed. An evaluation of the static and the dynamic coefficient of friction was performed, which was crucial for the understanding of the adhesion effects of the tested material pairing. The amount of information that is lost due to averaging the measured friction values is higher than one would expect.

Originality/value

The developed experimental setup is unique and, compared with the existing tribometers for testing under gas ambient pressures, allows testing under contact conditions that are closer to real applications, such as compressors and expanders. An in-depth observation of the adhesion and stick–slip effects of the tested material pairings is possible as well.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2023-0173/

Details

Industrial Lubrication and Tribology, vol. 75 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 13 November 2017

Andreas Rosenkranz, Saad Ahmed Khan, Adam Szurdak, Gerhard Hirt and Carsten Gachot

The purpose of this study is to investigate the influence of hemispherical structures fabricated by hot micro-coining on the resulting wear performance. Hemispherical structures…

137

Abstract

Purpose

The purpose of this study is to investigate the influence of hemispherical structures fabricated by hot micro-coining on the resulting wear performance. Hemispherical structures with different area densities (20 and 30 per cent), depths (50 and 100 µm) and diameters (100 and 200 µm) were fabricated by hot micro-coining on stainless steel samples.

Design/methodology/approach

The wear performance of these samples was studied using a ball-on-disk tribometer in rotational sliding mode using a normal load of 30 N and a fixed sliding velocity of 2 cm/s. Two different poly-(alpha)-olefin (PAO) oils without any additive having a kinematic viscosity of 4 and 40 cSt, were used to study the influence of the oil viscosity on the wear behavior.

Findings

Concerning the polished reference, an enlarged wear volume with an increase in the cycle number and the oil viscosity was observed. In the case of the micro-coined surfaces, all samples demonstrate a pronounced reduction in the wear volume (up to a factor of 100 for PAO 40) compared to the polished reference irrespective of the oil viscosity used.

Originality/value

This study details new research work studying the wear behavior of hot micro-coined surfaces.

Details

Industrial Lubrication and Tribology, vol. 69 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Available. Content available
Article
Publication date: 17 January 2025

Carsten Gachot

27

Abstract

Details

Industrial Lubrication and Tribology, vol. 77 no. 1
Type: Research Article
ISSN: 0036-8792

Available. Content available
Article
Publication date: 28 October 2024

Carsten Gachot

86

Abstract

Details

Industrial Lubrication and Tribology, vol. 76 no. 7/8
Type: Research Article
ISSN: 0036-8792

Available. Content available
Article
Publication date: 10 August 2015

Carsten Gachot

160

Abstract

Details

Industrial Lubrication and Tribology, vol. 67 no. 5
Type: Research Article
ISSN: 0036-8792

Available. Content available
Article
Publication date: 16 October 2020

Laszlo Katona

270

Abstract

Details

Industrial Lubrication and Tribology, vol. 72 no. 8
Type: Research Article
ISSN: 0036-8792

Available. Content available
Article
Publication date: 9 November 2020

Henara Costa and Giuseppe Pintaude

382

Abstract

Details

Industrial Lubrication and Tribology, vol. 72 no. 9
Type: Research Article
ISSN: 0036-8792

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