Special Issue "Selected Papers in the Sixth World Tribology Congress (WTC 2017)"

A special issue of Lubricants (ISSN 2075-4442).

Deadline for manuscript submissions: closed (31 January 2018)

Special Issue Editors

Guest Editor
Dr. Maria Isabel De Barros Bouchet

Laboratory of Tribology and System Dynamics (LTDS), Ecole Centrale de Lyon (ECL), 36 Avenue Guy de Collongue, 69134, ECULLY cedex, France
Website | E-Mail
Fax: +33 4 78 43 33 83
Interests: tribology; solid lubricants; additives of lubrication; gas phase lubrication; surfaces analyses; carbon-based coatings; superlubricity
Guest Editor
Dr. Giovanni Bolelli

Department of Engineering "Enzo Ferrari", University of Modena and Reggio Emilia, Via P. Vivarelli 10/1, I-41125 Modena (MO), Italy
Website | E-Mail
Fax: +39 059 2056243
Interests: thermal spray processes; physical vapour deposition (PVD); chemical vapour deposition (CVD); pack treatments; tribology of coatings; micromechanical characterization of coatings and surfaces; electrochemical corrosion testing; hot corrosion phenomena; residual stresses in coatings and surfaces

Special Issue Information

Dear Colleagues, 

The Sixth World Tribology Congress (WTC 2017) will be held in Beijing, China, on September 17–22, 2017, after the sessions in London (1997), Vienna (2001), Washington D.C. (2005), Kyoto (2009) and Torino (2013). WTC 2017 aims to highlight recent important progress in all aspects of tribology and strengthen the links between academia and industry.

The idea behind the Special Issue is to create a comprehensive collection of peer-reviewed articles that address the specific themes of research, that was covered on the WTC 2017. Please find a detailed description at following link: http://www.wtc2017.org/en. Contributions can be articles describing original research, methods, hypothesis and theory, opinions, and more traditional reviews. 20% discount of Article Processing Charges is available for all the attendees of WTC 2017. Researchers not attending the conference are also welcome to present their recent research, as well as review papers. Potential topics include, but are not limited to: 

  • Science of Tribology
  • Wear & Surface Engineering
  • Lubrication and Lubricants
  • Biotribology & Biomimetics
  • Tribology in Manufacturing
  • Engine and Transmission Tribology
  • Industrial Tribo-systems
  • Tribotest and Monitoring

Dr. Maria Isabel  De Barros Bouchet
Dr. Giovanni  Bolelli
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Lubricants is an international peer-reviewed open access quarterly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 350 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (7 papers)

View options order results:
result details:
Displaying articles 1-7
Export citation of selected articles as:

Research

Open AccessArticle Low Friction, Lubricity, and Durability of Polymer Brush Coatings, Characterized Using the Relaxation Tribometer Technique
Received: 16 March 2018 / Revised: 29 April 2018 / Accepted: 1 May 2018 / Published: 20 May 2018
PDF Full-text (2372 KB) | HTML Full-text | XML Full-text
Abstract
Among the possible solutions for achieving low friction, polymer brushes that are grafted onto surfaces are good candidates. The tribological characterization of such layers becomes more difficult when the friction is lower: the signal-to-noise ratio of the friction force that is measured with
[...] Read more.
Among the possible solutions for achieving low friction, polymer brushes that are grafted onto surfaces are good candidates. The tribological characterization of such layers becomes more difficult when the friction is lower: the signal-to-noise ratio of the friction force that is measured with conventional tribometers impedes the precise quantification. Therefore, we have applied a new technique that has been developed at the Laboratory of Tribology and System Dynamics (LTDS), called the ‘oscillating relaxation tribometer’. The advantage of this original technique is that it characterizes low friction with unequalled sensitivity. The lower the friction, the better the precision, and it permits obtaining the ‘friction law’ directly from robust and rapid experimental tests. In this study, the samples that have been used are the ionic liquid-type polymer brushes (ILPBs) with different thicknesses, which have been grafted onto silicon wafers and steel coupons. The counter-face is a mirror-polished steel ball. We show that (i) a thick ILPB layer on silicon is very resistant to high contact pressure, up to 555 MPa; (ii) the friction behavior that is obtained is close to that of a Newtonian viscous one, even under maximum normal loads; (iii) poorer results are obtained for the thinner sample; and (iv) the repetition, up to 5000 oscillations on the same surface, does not affect the friction damping of the contact, which demonstrates that this film provides a favorable resistance to friction under severe contact conditions. In addition, the feasibility of grafting onto steel surfaces is demonstrated. The results are then discussed, with respect to friction and dissipation. Full article
(This article belongs to the Special Issue Selected Papers in the Sixth World Tribology Congress (WTC 2017))
Figures

Graphical abstract

Open AccessArticle Detailed Investigations on the Oil Flow in Dip-Lubricated Gearboxes by the Finite Volume CFD Method
Received: 9 February 2018 / Revised: 10 April 2018 / Accepted: 2 May 2018 / Published: 9 May 2018
PDF Full-text (14730 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Three main concerns are in the focus of the development of geared transmissions nowadays: load carrying capacity, noise–vibration–harshness (NVH) behavior, and efficiency. Increasing the efficiency of modern gearboxes contributes significantly to the reduction of energy consumption and the saving of resources. Gearboxes are
[...] Read more.
Three main concerns are in the focus of the development of geared transmissions nowadays: load carrying capacity, noise–vibration–harshness (NVH) behavior, and efficiency. Increasing the efficiency of modern gearboxes contributes significantly to the reduction of energy consumption and the saving of resources. Gearboxes are frequently designed conservatively with an oversupply of oil to guarantee operational reliability. An oversupply of oil results in an unnecessarily high amount of oil kept in motion and to high no-load losses. Detailed information on the oil distribution in the early design stages of gearboxes would help to optimize the lubrication and to increase the efficiency. Thereby, CFD (computational fluid dynamics) methods offer a very flexible way to visualize the oil flow inside gearboxes with much fewer restrictions compared to measurements with transparent gearbox designs. In this study, a verified CFD model based on the finite volume method is used to investigate the oil flow in a single-stage gearbox. Different oil viscosities and circumferential speeds are considered. The investigations focus on the oil flow. The gear churning loss, as part of the no-load loss, is additionally considered. Experimental validation is obtained by high-speed camera recordings and measurements at the FZG no-load power loss test rig. The results show very strong agreement between simulation and measurement. The results show that CFD simulations can visualize the oil flow behavior with a very high degree of detail. Full article
(This article belongs to the Special Issue Selected Papers in the Sixth World Tribology Congress (WTC 2017))
Figures

Graphical abstract

Open AccessArticle Ab Initio Molecular Dynamics Simulation of Tribochemical Reactions Involving Phosphorus Additives at Sliding Iron Interfaces
Received: 22 March 2018 / Revised: 30 March 2018 / Accepted: 4 April 2018 / Published: 5 April 2018
Cited by 1 | PDF Full-text (8227 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
We performed, for the first time to our knowledge, fully ab initio molecular dynamics simulations of additive tribochemistry in boundary lubrication conditions. We consider an organophosphourus additive that has been experimentally shown to reduce friction in steel-on-steel sliding contacts thanks to the tribologically-induced
[...] Read more.
We performed, for the first time to our knowledge, fully ab initio molecular dynamics simulations of additive tribochemistry in boundary lubrication conditions. We consider an organophosphourus additive that has been experimentally shown to reduce friction in steel-on-steel sliding contacts thanks to the tribologically-induced formation of an iron phosphide tribofilm. The simulations allow us to observe in real time the molecular dissociation at the sliding iron interface under pressure and to understand the mechanism of iron phosphide formation. We discuss the role played by the mechanical stress by comparing the activation times for molecular dissociation observed in the tribological simulations at different applied loads with that expected on the basis of the dissociation barrier. Full article
(This article belongs to the Special Issue Selected Papers in the Sixth World Tribology Congress (WTC 2017))
Figures

Figure 1

Open AccessArticle An Alternative Approach to Simulating an Entire Particle Erosion Experiment
Received: 1 February 2018 / Revised: 16 March 2018 / Accepted: 17 March 2018 / Published: 20 March 2018
PDF Full-text (3177 KB) | HTML Full-text | XML Full-text
Abstract
Solid particle erosion affects many areas, such as dust or volcanic ash in areo-engines. The development of protective materials and surface engineering is costly and time consuming. A lot of effort has been placed into the advancement of models to speed up this
[...] Read more.
Solid particle erosion affects many areas, such as dust or volcanic ash in areo-engines. The development of protective materials and surface engineering is costly and time consuming. A lot of effort has been placed into the advancement of models to speed up this process. Finite element or discrete element-based models are quite successful in predicting single or multiple impacts. However, they reach their limit if an entire erosion experiment is to be simulated. Therefore, in the present work, an approach is presented which combines various aspects of the former models with probability considerations. It is used to simulate the impact of more than one billion Alumina particles onto a steel substrate. This approach permits the simulation of an entire erosion experiment on an average PC (i5-2520M CPU@2.5 GHz processor, 4 GB main memory) within about six hours. The respective predictions of wear scar and impact-mass/mass-loss curve are compared to the real experiment. Full article
(This article belongs to the Special Issue Selected Papers in the Sixth World Tribology Congress (WTC 2017))
Figures

Graphical abstract

Open AccessArticle Tribological Behavior of HNBR in Oil and Gas Field Applications
Received: 10 January 2018 / Revised: 8 February 2018 / Accepted: 11 February 2018 / Published: 13 February 2018
PDF Full-text (6563 KB) | HTML Full-text | XML Full-text
Abstract
The common usages of elastomeric components in oil and gas field applications are in dynamic atmospheres; especially sealing appliances that are in relative motion when interacting with surfaces. Therefore, their performance and service life mainly depend on the wear and friction characteristics in
[...] Read more.
The common usages of elastomeric components in oil and gas field applications are in dynamic atmospheres; especially sealing appliances that are in relative motion when interacting with surfaces. Therefore, their performance and service life mainly depend on the wear and friction characteristics in use. The objective of this scientific work is to identify the effect of swelling-induced ageing on the tribological properties and surface damage mechanisms of hydrogenated nitrile butadiene rubber (HNBR) in contact with different liquids. Furthermore, the investigation of the co-relation between mechanical properties and surface properties in the tested conditions is indispensable. In the swollen state, deteriorated mechanical properties were observed; however, in de-swollen conditions, the mechanical properties were restored. As far as the surface characterization is concerned, when the HNBR was swollen by a standard IRM 903 solvent, its wear was greater compared with the un-swollen specimen (1.1 times) despite the lower coefficient of friction (COF) (reduced by ~25%) and surface temperature (reduced by ~2.4 °C). In the de-swollen condition, wear was even greater (6 times), but the COF and surface temperature were situated in between those recorded in the swollen and un-swollen conditions. With swelling, greater wear damage and lower COF were observed; higher surface ageing (softness), which eases crack growth, created bigger debris. Under the conditions used, in the de-swollen states, the bulk mechanical properties were almost recovered, in contrast to the surface properties, which were still significantly impaired. Full article
(This article belongs to the Special Issue Selected Papers in the Sixth World Tribology Congress (WTC 2017))
Figures

Graphical abstract

Open AccessArticle TEHL Simulation on the Influence of Lubricants on the Frictional Losses of DLC Coated Gears
Received: 6 December 2017 / Revised: 17 January 2018 / Accepted: 31 January 2018 / Published: 10 February 2018
PDF Full-text (2761 KB) | HTML Full-text | XML Full-text
Abstract
Diamond-Like Carbon (DLC) coatings can reduce fluid friction in TEHL contacts (thermo-elastohydrodynamic lubrication) of meshing gears. This study investigates the influence of different base oils i.e., mineral, polyalphaolefin and polyglycol oil on the friction of DLC coated spur gears. Thereby, a transient TEHL
[...] Read more.
Diamond-Like Carbon (DLC) coatings can reduce fluid friction in TEHL contacts (thermo-elastohydrodynamic lubrication) of meshing gears. This study investigates the influence of different base oils i.e., mineral, polyalphaolefin and polyglycol oil on the friction of DLC coated spur gears. Thereby, a transient TEHL simulation model based on the finite element based full-system approach coupled iteratively with the thermal equations is applied, considering mechanical and thermal properties of the DLC coatings. Results show a clear reduction of fluid friction in DLC coated gears for all considered lubricants. This can be traced back to higher TEHL temperatures for DLC coated gears, which is due to its low thermal inertia resulting in a thermal insulation effect. Full article
(This article belongs to the Special Issue Selected Papers in the Sixth World Tribology Congress (WTC 2017))
Figures

Figure 1

Open AccessArticle Influence of Laser Pulse Number on the Ablation of Cemented Tungsten Carbides (WC-CoNi) with Different Grain Size
Received: 6 December 2017 / Revised: 15 January 2018 / Accepted: 16 January 2018 / Published: 20 January 2018
PDF Full-text (3596 KB) | HTML Full-text | XML Full-text
Abstract
The ultra-short pulse laser has attracted attention as an advanced tool for functionalizing surface topography, since it has high accuracy and results in little damage. In a previous study, some innovative patterns were introduced on cemented carbide surfaces, such as dimples, which are
[...] Read more.
The ultra-short pulse laser has attracted attention as an advanced tool for functionalizing surface topography, since it has high accuracy and results in little damage. In a previous study, some innovative patterns were introduced on cemented carbide surfaces, such as dimples, which are commonly used as oil reservoirs for bearings. The accuracy is not only related to the inherent features of the laser, but also to the machining processes. Within this context, this study aims to investigate the influence of machining parameters (i.e., pulse number in this study) on the ablation mechanism and resulting surface integrity. Two cemented carbide grades, possessing similar chemical composition but different grain size (small and large), are machined using a femtosond laser set-up with variant pulse number (1–20). The geometrical properties of the produced structure and surface integrity are statistically investigated using different microscopy techniques. It is found that the dimple depth is approximately proportional to the pulse number for both grades, and the coarse grade leads to a higher rate of depth increase. Damage is found in the form of melting and cracking for the binder and the grains, respectively; but this is more pronounced for large-grain grade in terms of the scale and depth. However, these observations are only found at a very superficial position. Full article
(This article belongs to the Special Issue Selected Papers in the Sixth World Tribology Congress (WTC 2017))
Figures

Graphical abstract

Back to Top