Influence of defects and morphology of diamond-like carbon coatings on their tribological behaviour

The aim of the study was to analyze the superhard anti-wear diamond-like carbon coatings produced by Plasma Assisted Chemical Vapor Deposition (PACVD) and Physical Vapour Deposition (PVD). The a-C:H and a-C:H:W coatings were deposited on steel elements operating under friction conditions. The analysis involved comparing the tribological properties of coated metal elements with those of uncoated elements. It was essential to analyze how the coating composition and structure influence the tribological behaviour of elements under dry and lubrication friction conditions. The coating structure was analyzed by observing the topography of the surface and the cross-sections using an atomic force microscope (AFM) and a scanning electron microscope (SEM). The results were employed to determine the elemental composition and thickness of the coatings. The tribological tests were performed applying a ball-on-disc tribometer and using a pin-on-plate tribometer. The tribological properties were analyzed also in a micro scale using a microtribometer. Compared with the substrate material - steel, the diamond-like carbon coatings showed lower linear wear, lower friction coefficient and higher hardness.

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Tribological Performance of Si-Doped Hydrogenated Diamond-Like Carbon Coatings in Different Biodiesel

Journal of Applied Chemistry ◽

10.1155/2016/1307691 ◽

2016 ◽

Vol 2016 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

Annett Dorner-Reisel ◽

Zeynep Burcu Kavaklioglu ◽

Stefan Svoboda ◽

Jürgen Engemann

Keyword(s):

Methyl Ester ◽

Biodiesel Production ◽

Diamond Like Carbon ◽

Tribological Behaviour ◽

Carbon Coatings ◽

Wear Rates ◽

Si Doped ◽

Silicon Doped ◽

Polar Functional Groups

In this paper, two kinds of different biodiesel were tested in terms of their impact on wear resistance of Si-DLC coated 100Cr6 flat worn by an oscillating 100Cr6 ball. The knowledge about the tribological behaviour of different types of biodiesel is rare. Rape and soybean are two of the most common natural sources for biodiesel production. Also, if the quality of biodiesel seems to be similar and, according to the demands, biodiesel from different natural origin could affect changes in the tribological behaviour. Although, soybean methyl ester (SME) gives the best results at room temperature wear tests, 150°C SME reaches wear rates of Si-DLC flat against 100Cr6 ball almost double as high as rapeseed methyl ester (RME). It is evident that, with increasing fraction of oxidation stabilizer C23H32O2, the wear rate increases. For silicon doped hydrogenated diamond-like carbon is especially suitable, for use in biodiesels, where certain fraction of humidity, dissociated water, or polar functional groups may present.

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Effect of test atmosphere on the tribological behaviour of the non-hydrogenated diamond-like carbon coatings against 319 aluminum alloy and tungsten carbide

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2005.08.053 ◽

2005 ◽

Vol 200 (5-6) ◽

pp. 1783-1791 ◽

Cited By ~ 44

Author(s):

E. Konca ◽

Y.-T. Cheng ◽

A.M. Weiner ◽

J.M. Dasch ◽

A.T. Alpas

Keyword(s):

Aluminum Alloy ◽

Tungsten Carbide ◽

Diamond Like Carbon ◽

Tribological Behaviour ◽

Carbon Coatings ◽

Test Atmosphere ◽

And Tungsten

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Tribological behaviour of diamond-like carbon coatings at high rates of sliding

Diamond and Related Materials ◽

10.1016/0925-9635(93)90240-3 ◽

1993 ◽

Vol 2 (5-7) ◽

pp. 866-868 ◽

Cited By ~ 6

Author(s):

I.I. Aksenov ◽

M.G. Maksimov ◽

Yu.Ya. Palij ◽

V.E. Strel'nitskij

Keyword(s):

Diamond Like Carbon ◽

Tribological Behaviour ◽

Carbon Coatings

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Interplay of mechanics and chemistry governs wear of diamond-like carbon coatings interacting with ZDDP-additivated lubricants

Nature Communications ◽

10.1038/s41467-021-24766-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Valentin R. Salinas Ruiz ◽

Takuya Kuwahara ◽

Jules Galipaud ◽

Karine Masenelli-Varlot ◽

Mohamed Ben Hassine ◽

...

Keyword(s):

Friction And Wear ◽

Contact Stiffness ◽

Diamond Like Carbon ◽

Tribological Behaviour ◽

Mechanical Mixing ◽

Carbon Coatings ◽

Engine Oils ◽

Tetrahedral Amorphous Carbon ◽

Wear Reduction ◽

Low Wear

AbstractFriction and wear reduction by diamond-like carbon (DLC) in automotive applications can be affected by zinc-dialkyldithiophosphate (ZDDP), which is widely used in engine oils. Our experiments show that DLC’s tribological behaviour in ZDDP-additivated oils can be optimised by tailoring its stiffness, surface nano-topography and hydrogen content. An optimal combination of ultralow friction and negligible wear is achieved using hydrogen-free tetrahedral amorphous carbon (ta-C) with moderate hardness. Softer coatings exhibit similarly low wear and thin ZDDP-derived patchy tribofilms but higher friction. Conversely, harder ta-Cs undergo severe wear and sub-surface sulphur contamination. Contact-mechanics and quantum-chemical simulations reveal that shear combined with the high local contact pressure caused by the contact stiffness and average surface slope of hard ta-Cs favour ZDDP fragmentation and sulphur release. In absence of hydrogen, this is followed by local surface cold welding and sub-surface mechanical mixing of sulphur resulting in a decrease of yield stress and wear.

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Friction and Wear of Diamond-Like Carbon Coatings Lubricated With Biodegradable Oils

World Tribology Congress III, Volume 2 ◽

10.1115/wtc2005-63340 ◽

2005 ◽

Author(s):

K. Van Acker ◽

K. Vercammen ◽

A. Vanhulsel ◽

J. Barriga ◽

A. Arnsek ◽

...

Keyword(s):

Unsaturated Ester ◽

Diamond Like Carbon ◽

Tribological Behaviour ◽

Low Friction ◽

Carbon Coatings ◽

Base Oil ◽

Biodegradable Oils ◽

Coating Type ◽

Si Doped ◽

Ball On Disc

The tribological behaviour of coated machine components lubricated with a biodegradable saturated ester and unsaturated ester oil has been studied. Different diamond-like carbon-based coatings (DLC) were selected as low friction coatings: pure DLC, Si-doped, Ti-doped and W-doped DLC. The performance of the studied ester oils has been compared with sunflower oil and mineral oil lubrication as reference. The oils were all additivated in the same way with conventional anti-wear (AW) and extreme pressure (EP) additives. Different tests have been performed: disc on disc, ball on disc and block on ring tests give an overview of the influence of different sliding modes. The effect of the lubricant on a coated system compared to the use of the coated system without lubrication is clear for the wear, but less obvious for the friction. It was found that DLC/DLC contacts lubricated with biodegradable lubricants show similar friction as steel/steel contacts. The effect of the different types of base oil is independent of the coating type. Additive activity which was clear in steel/steel contacts was not obvious in DLC/DLC contacts.

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