Interaction of DLC and B4C coatings with fully formulated oils in boundary lubrication conditions

Tamura, Yukio; Zhao, Hongyuan; Wang, Chun; Morina, Ardian; Neville, Anne

doi:10.1016/j.triboint.2015.02.029

Cited by 28 publications

(8 citation statements)

References 37 publications

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“…The spectra of photoelectron states obtained with a high resolution and describing the chemical bonds characteristic of each element in the coating, namely the C1s peak (at 284.8 eV), the B1s (191 eV) and O1s (538 eV) peaks were subjected to further analysis [20,21]. with the presence of more than one heterophase in the coating (carbon, carbide) [42,43]. Quantity of heterophase forms the structure, as well as with chemical processes occurring in the volume of the coating leads to the formation of carbide compound and boron oxide compound on the coating surface.…”

Section: Resultsmentioning

confidence: 99%

Boron-Carbon Coatings: Structure, Morphology, and Mechanical Properties

Kulesh

Piliptsou

Rogachev

et al. 2020

JES

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Boron-doped carbon coatings have been produced by a method combining the deposition of a pulsed carbon plasma coating and a boron flow formed as a result of the evaporation of a boron target by pulsed YAG: Nd3+ laser irradiation. Phase, chemical composition, structure, and mechanical properties of composite boron-carbon coatings have been determined. Changes in the coatings’ roughness depending on the boron concentration have been established using atomic force microscopy. It has been shown that the grain size is on the rise with increasing boron concentration. Raman spectroscopy has revealed that at a boron concentration of 43.2 at. %. There is a sharp increase in the ID/IG ratio, which indicates the carbon component’s graphitization. Low ID/IG ratios are observed in the coating at low boron concentrations (no more than 17.4 at. %), suggesting a high content of carbon atoms with sp3 bond hybridization. The coating studies, carried out by X-ray photoelectron microscopy, showed that boron could be in a free state or in the form of carbide or oxide depending on the concentration in the coating. In this case, with an increase in boron concentration, there is a decrease in the concentration of carbon atoms in the state with sp3 bond hybridization, accompanied by an increase in the number of B-C bonds and a reduction in the boron concentration not associated with carbon and oxygen. These coating and chemical composition features determine the boron concentration’s established non-monotonic nature on their microhardness, elastic and mechanical properties. Keywords: composite carbon coatings, boron-doped, atomic force microscopy, X-ray photoelectron microscopy, Raman spectroscopy, microhardness, scratch.

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Section: Resultsmentioning

confidence: 99%

Boron-Carbon Coatings: Structure, Morphology, and Mechanical Properties

Kulesh

Piliptsou

Rogachev

et al. 2020

JES

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“…During the friction tests under the 85 % RH condition, the oxidation product of WO 3 can act as a "lubricant", and then a thin tribo-chemical film containing WO 3 can be formed on the sliding interfaces. This is propitious to reduce the fric-tion coefficient and enhance the wear resistance [25][26][27]. While the steel ball was oxidised to form Fe(OH) 3 which could bring about the strong adhesion at the sliding interfaces [28], and, further, results in a higher average friction coefficient of the B 4 C/steel tribopair.…”

Section: Discussionmentioning

confidence: 99%

Tribological Investigation of Boron Carbide Films Sliding Against Different Mating Materials Under High Relative Humidity

Cao¹

2019

Ceramics - Silikaty

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Tribological performances are significantly affected by the tribo-chemical reaction of the mating materials, while the effect on the B 4 C film under high relative humidity conditions are poorly investigated. Therefore, fiction tests of three tribo-pairs (B 4 C/WC, B 4 C/steel and B 4 C/Al 2 O 3) under 85 % RH with various normal loads and sliding frequencies were performed. The results show that the B 4 C/WC tribo-pair exhibits excellent tribological properties, including very stable friction curves, minimum friction coefficients & wear rates, maximum carrying-load capacity and the smallest fluctuations with the change of the normal load. Similar results have been obtained for the B 4 C/WC tribo-pair with the increase in the sliding frequency. This is mainly attributed to the oxidation of WC to form WO 3 that is conducive in enhancing the tribological performances. Therefore, the sliding contact of B 4 C/WC is the desirable design for engineering applications under high relative humidity.

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“…where β is the average asperity tip radius, σ is the composite RMS surface parameter, A is the apparent contact area, is the reduced elastic modulus of contact, as shown in Equation ( 9) and F 5/2 (λ) is a statistical function for Gaussian distribution of asperities affected by the Stribeck oil film parameter λ and is described by Equation (10).…”

Section: Loaded Gear Frictional Losses Considering Uncoated Surfacementioning

confidence: 99%

“…Despite complications related to the properties of DLC coatings and sensitivity to specific operating conditions, their advantages can undoubtedly contribute to the reduction of gearbox power losses. Consequently, their use has been tested experimentally by various researchers [2,9,10]. However, there is a dearth of reported work on modelling the tribo-dynamics of DLC coated transmission gears compared to thorough research of helical gear performance [11] and dynamic contacts [12] in general.…”

Section: Introductionmentioning

confidence: 99%

On the Effect of DLC and WCC Coatings on the Efficiency of Manual Transmission Gear Pairs

et al. 2020

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An experimentally validated tribo-dynamic model has been developed to predict the gear teeth frictional losses considering the properties of the diamond-like-carbon (DLC)-coated and tungsten carbide carbon (WCC)-coated surface. The operating conditions used are snapshots of the Real Driving Emissions (RDE) driving cycle. The results demonstrate that the use of these coatings can improve the frictional losses up to 50%. The gear teeth boundary friction model is enriched by experimentally measured coefficients of the surface asperity boundary shear strength using an atomic force microscope (AFM). The computationally efficient model enables the efficiency prediction in a complete transmission. Such an approach, considering the contact mechanics of coated gear and their effect on the viscous and boundary friction, has not been hitherto reported.

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Interaction of DLC and B4C coatings with fully formulated oils in boundary lubrication conditions

Cited by 28 publications

References 37 publications

Boron-Carbon Coatings: Structure, Morphology, and Mechanical Properties

Boron-Carbon Coatings: Structure, Morphology, and Mechanical Properties

Tribological Investigation of Boron Carbide Films Sliding Against Different Mating Materials Under High Relative Humidity

On the Effect of DLC and WCC Coatings on the Efficiency of Manual Transmission Gear Pairs

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