Effect of soft substrate topography on tribological behavior of multifunctional DLC coatings

Soprano, Pedro Besen; Salvaro, Diego Berti; Giacomelli, Renan Oss; Binder, Cristiano; Klein, Aloı́sio Nelmo; Mello, José Daniel Biasoli de

doi:10.1007/s40430-018-1290-6

Cited by 11 publications

(6 citation statements)

References 32 publications

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“…According to Al Mahmud et al [47], the higher the ID/IG ratio the greater the number of sp 2 bonds in the ring structure of the film, indicating a reduction in the amount of sp 3 bonds. Soprano et al obtained ID/IG variations from 0.64 to 0.72 with different samples' texturing conditions produced via sanding processes, and indicated that these variations were not significant [29]. The bands' positions (D and G), ID/IG ratio and the percentage of hydrogen in the present work were similar to the values in Soprano´s work.…”

Section: Discussionsupporting

confidence: 83%

“…The combination of multilayers (such as CrN + DLC) increases the loading capacity of the substrate, improving adhesion and leading to a more favorable stress distribution [28]. Plasma nitriding of the substrate is another approach to improve load-bearing capacity before DLC deposition [29]. It allows progressively increase surface hardness, creating mechanical support for the DLC coating [30].…”

Section: Introductionmentioning

confidence: 99%

“…The adhesion between the DLC coating and the softer substrate is particularly relevant for a textured surface, since the surface topography affects this adhesion [31]. Moreover, the surface roughness of the substrate has a strong effect on the friction and wear of DLCs [29,31]. The microstructure of the nitrided zone consists of a compound layer (surface layer) and a diffusion zone underneath the compound layer.…”

Section: Introductionmentioning

confidence: 99%

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Combined Use of Surface Texturing, Plasma Nitriding and DLC Coating on Tool Steel

et al. 2021

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In cold rolling, a textured roll can be used to imprint a desired surface topography onto the sheet during rolling. This work proposes the use of diamond-like carbon (DLC) coatings to protect the surface topography of the rolls in replacement of the carcinogenic hard chrome. For that, hydrogenated amorphous carbon (a-C:H) was deposited on plasma nitrided tool steel, both for ground and textured specimens. Changes in surface topography due to DLC coating were assessed using a confocal microscope. Coating adhesion was evaluated using the method VDI 3198. The specimens were characterized using X-ray diffraction (XRD), microhardness test and scanning electron microscopy (SEM). The coating was characterized using Raman spectroscopy (RS) and X-ray photoelectron spectroscopy (XPS). The results showed a soft multilayer coating consisting of a plasma nitrided layer for load support, a Si-rich interlayer to improve adhesion and an a-C:H top layer. DLC deposition reduced the roughness of the textured specimens. The coating resulted in relatively stable friction and good durability, with small damage and negligible wear even under dry sliding.

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Section: Discussionsupporting

confidence: 83%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Combined Use of Surface Texturing, Plasma Nitriding and DLC Coating on Tool Steel

et al. 2021

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“…To understand how the surface finishing (five different conditions) of a soft substrate influences the tribological behavior of hydrogenated amorphous carbon (a-C:H) films, DLC coating was applied on plasma-nitrided low carbon steel substrates. Both processes happened in a single PECVD batch (Soprano et al, 2018). The mechanical properties and bonding structures of the a-C:H films are negligibly affected by the substrate topography.…”

Section: Substrate Surface Finishingmentioning

confidence: 99%

In situ Tribo-Fluorination for Oil-Less Hermetic Compressor Applications

et al. 2021

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In the present work, we overview the multidisciplinary development of a regular, lubricated, hermetic compressor which works in an on-off cycle, circular motion, single-speed, many tribological contacts, into an innovative, linear motion, variable displacement, single tribological contact, oil-less hermetic compressor presenting high versatility in terms of refrigerator design, sustainability and improved efficiency. The original approach encompassed the development of new surface engineering procedures applying purpose-oriented phases to soft substrates. Particular emphasis is given to the in situ fluorination of the tribolayer formed in the piston-cylinder tribopair. Although chlorinated halocarbons (CFC) are efficient refrigerants from a thermodynamic point of view, they do have serious environmental implications that have forced the refrigeration industry to switch to more environmentally friendly hydrofluorocarbon (HFC) based refrigerants. The first and most successful alternative to the CFCs was tetrafluorocarbon, particularly tetrafluoroethane (CF3CH2F), aka R134a refrigerant. The current trend to downsizing mechanical systems, smaller clearances, and increased speeds leading to greater energy efficiencies associated with miscibility issues imposing the use of costly, fully synthetic lubricants with the R134a refrigerant gas led to the introduction of a new hermetic compressor design, the Wisemotion®, the first, and until now, unique, oil-free hermetic compressor on the world market. In this context different types of multi-layers, their thickness, substrate material, processing routes, etc., have been studied and optimized. Si-rich hydrogenated DLC (a:C-H) presented enhanced tribological properties when tested under fluorine-rich atmospheres, and semi-industrial scale tests have been carried out to understand this point further. A homemade tribological emulator was developed allowing close-to-real tribopair, atmosphere, and imposed mechanical conditions used in an oil-free commercial hermetic compressor. The tests were carried under different stroke frequencies (5, 20, and 40 Hz) and atmospheres (R134a, ambient air, and argon). Results showed a strong influence of both atmosphere and stroke frequencies. The friction coefficients were significantly lower (~3.8X) for the refrigerant gas atmosphere, attributed to the fluorine and highly disordered graphitic structures rich tribolayers. Under the high frequency (40 Hz), the energy input seems to be a deterrent to the formation of stable tribolayers, and the DLC coating shatters on the first few sliding meters.

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“…The final coating thicknesses reach 5 µm for both coatings. The roughness of the substrate has little effect on the final roughness and thickness of the coating [31]. Coating treatment is done in accordance with the following conditions: vacuum degree 225 Torr, furnace temperature 400 °C, reaction gas N2, plating time 140 min and protection gas N2.…”

Section: Sample Preparationmentioning

confidence: 99%

Nanoscale characterization of Titanium-based coatings plastic properties by dimensional analysis, FEA and Infimum resultant error criterion

Bazzaz

Darvizeh

Alitavoli

et al. 2020

J Braz. Soc. Mech. Sci. Eng.

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Working with continuously harder materials and higher cutting speeds requires novel mechanical properties for cutting tools. The application of titanium-based coatings deposited by PVD is experienced as one of the most effective solutions. To assure achievement of the required characteristics in the metal cutting process, which mainly includes turning, milling, drilling and some other methods, extracting the plastic properties has been the main challenge for a long time. In this paper, a hybrid method emerging the modified dimensional analysis method (MDAM) and experimental data with novel algorithm named as minimum resultant error method is proposed. By using this algorithm, yield stress, strain hardening exponent and strain hardening coefficient are extracted as unique measures via using a single indenter nanoindentation result. An existing experimental output data and numerical solution of TiN thin film nanoindentation test are used to verify the proposed approach. The same procedure is implemented to calculate the plastic properties of TiAlN coating. Some of the results for TiAlN are among the rarely investigated matters. The effects of mesh refinement, friction coefficient and indenter tip radius are elucidated. According to the results attained from the new approach, there is an excellent agreement between MDAM and the combined algorithm results (4% for yield stress and 7% for strain hardening exponent). The resultant error is calculated in the range of 0.47-4.1% for optimized deviation. To provide another criterion of the adaptability of the results, the elastic modulus and hardness are calculated within less than 5% and 9% errors, respectively.

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Effect of soft substrate topography on tribological behavior of multifunctional DLC coatings

Cited by 11 publications

References 32 publications

Combined Use of Surface Texturing, Plasma Nitriding and DLC Coating on Tool Steel

Combined Use of Surface Texturing, Plasma Nitriding and DLC Coating on Tool Steel

In situ Tribo-Fluorination for Oil-Less Hermetic Compressor Applications

Nanoscale characterization of Titanium-based coatings plastic properties by dimensional analysis, FEA and Infimum resultant error criterion

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