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Article

Influence of Gear Set Loading on Surface Damage Forms for Gear Teeth with DLC Coating

by
Edyta Osuch-Słomka
1,*,
Remigiusz Michalczewski
1,
Anita Mańkowska-Snopczyńska
1,
Michał Gibała
1,
Andrzej N. Wieczorek
2 and
Emilia Skołek
3
1
Łukasiewicz Research Network-Institute for Sustainable Technologies (Ł-ITEE), ul. Pulaskiego 6/10, 26-600 Radom, Poland
2
Faculty of Mining, Safety Engineering and Industrial Automation, Silesian University of Technology, ul. Akademicka 2, 44-100 Gliwice, Poland
3
Faculty of Materials Science and Engineering, Warsaw University of Technology, ul. Wołoska 141, 02-507 Warsaw, Poland
*
Author to whom correspondence should be addressed.
Coatings 2025, 15(7), 857; https://doi.org/10.3390/coatings15070857
Submission received: 27 June 2025 / Revised: 17 July 2025 / Accepted: 18 July 2025 / Published: 21 July 2025

Abstract

An analysis of the working surfaces of cylindrical gears after scuffing shock tests allowed for the assessment of the effect of loading conditions on the form of damage to the tooth surfaces. Unlike the method of scuffing under severe conditions, where loading is applied gradually, the presented tests employed direct maximum loading—shock loading—without prior lapping of the gears under lower loads. This loading method significantly increases the vulnerability of the analyzed components to scuffing, enabling an evaluation of their limit in terms of operational properties. To identify the changes and the types of the teeth’s working surface damage, the following microscopy techniques were applied: scanning electron microscopy (FE-SEM) with EDS microanalyzer, optical interferential profilometry (WLI), atomic force microscope (AFM), and optical microscopy. The results allowed us to define the characteristic damage mechanisms and assess the efficiency of the applied DLC coatings when it comes to resistance to scuffing in shock scuffing conditions. Tribological tests were performed by means of an FZG T-12U gear test rig in a power circulating system to test cylindrical gear scuffing. The gears were made from 18CrNiMo7-6 steel and 35CrMnSiA nano-bainitic steel and coated with W-DLC/CrN.

1. Introduction

The problem of friction pair scuffing remains a topical issue in the design and operation of machines. This is due to the growing tendency to increase the loads transmitted by friction elements while simultaneously reducing their size, which significantly intensifies tribological phenomena. In tribological research, a particularly important question is to what extent the results of tribological tests conducted under laboratory conditions can be extrapolated to machine components operating under real-world conditions. This question primarily concerns the properties of the materials from which the operating friction pairs are made. Coal mines are characterized by very harsh operating conditions, where the working surfaces of drive train gears are at risk of severe damage. The gearbox oil is polluted with solid particles. Similar difficult conditions can be found in construction, forestry, or agricultural industries. As a result, the gearbox service life is shortened. In extreme situations, a weakened tooth can break, removing the gearbox from exploitation. To prevent the problem of intense wear and lengthen the service life of gearboxes, tooth surfaces are modified in different ways, including the application of thin, low-friction coatings. Currently, DLC coatings (DLC—diamond-like carbon) are the most frequently tested when it comes to tribological properties. Good anti-scuffing qualities result from the presence of amorphous carbon (sp2) in the outer layer of the coating. Various types of diamond-like carbon coatings have been explored for improving gear performance, including tungsten-doped DLC (W-DLC), chromium-doped DLC (Cr-DLC), and silicon-doped DLC (Si-DLC). For example, Evaristo et al. [1] demonstrated that alloying elements significantly influence the tribological behavior of DLC coatings under different sliding conditions. Similarly, Forsberg et al. [2] showed enhanced performance of DLC coatings in heated engine oils, indicating improved thermal stability. Rincon et al. [3] investigated multilayer tungsten carbide/DLC coatings, revealing their effectiveness in terms of increasing wear resistance on steel substrates. Goti et al. [4] reported on super-hard tantalum-carbide-doped DLC coatings produced by low-temperature PVD, which showed superior hardness and wear resistance. Other studies, such as those by Rajak et al. [5] and Shaikh et al. [6], provide comprehensive reviews of DLC classification and tribological properties, emphasizing the benefits of doped DLC films in reducing friction and wear. Diamond-like carbon coatings doped with tungsten (W-DLC) have demonstrated enhanced tribological performance, particularly when lubricated with cutting fluids, as shown by Radoń-Kobus et al. [7]. Martins et al. [8] reported that low-friction coatings significantly improve the scuffing load capacity and efficiency of gears. Studies by Vengudusamy et al. [9] highlighted the friction-reducing properties of DLC/DLC contacts in base oils, while Kalin and Vižintin [10] investigated the performance of DLC-coated gears under biodegradable oil lubrication, noting improved wear resistance across various gear materials. Tuszyński et al. [11] examined abrasive wear, scuffing, and rolling contact fatigue in DLC and WC/C-coated steels used in harsh mining conditions, confirming the coatings’ effectiveness in prolonging gear life. Vicen et al. [12] conducted research on the effect of tungsten-doped diamond-like carbon (W-DLC) coatings on the corrosion and tribological properties of 100Cr6 steel under simulated seawater conditions. Further research by Barth et al. [13] explored improvements in the wear behavior of water-based lubricants for gears, complementing findings on carbon-based coatings’ tribological benefits under high load by Ronkainen et al. [14]. The thermal and mechanical behavior of DLC-coated gears has also been extensively studied. Beilicke et al. [15] performed transient thermal elastohydrodynamic simulations on DLC-coated helical gear pairs, accounting for the limiting shear stress behavior of lubricants, which provided insight into load-carrying capacity improvements under operating conditions. Liu et al. [16] conducted tribological evaluations of coated spur gear pairs, confirming enhanced wear resistance and friction reduction. Fujii et al. [17] investigated the surface durability of WC/C-coated case-hardened steel gears, reporting improved resistance to surface damage. Furthermore, Wu et al. [18] conducted a review of recent advances in improving the wear resistance of metal components coated with diamond-like carbon (DLC) coatings during service.
The results, identifying changes on the working surfaces of drive train gears made from 18CrNiMo7-6 and 35CrMnSiA steel and coated with W-DLC/CrN, after scuffing (FZG) tests under severe conditions with gradually increasing loading of the friction pair, were presented in [19]. To further analyze the damage mechanisms, the tests were continued by considering shock loading during the operation of cylindrical toothed gears, which corresponds with the dynamic, sudden overloading typical of emergency conditions or harsh environments. The purpose of the tests was to determine the effect of the loading method on the form of damage to the teeth’s working surfaces by analyzing changes using microscopy methods.

2. Materials and Methods

The shock scuffing tests were conducted on FZG A10 test gears (Forschungsstelle fur Zahnrader und Getriebebau, FZG of the Technical University of Munich, Germany) with a 10 mm wide pinion and a 20 mm wide gear. The working surfaces of the teeth were ground longitudinally (Figure 1). Key gear parameters were as follows: number of teeth on the pinion—16, number of teeth on the gear—24, module—4.5, center distance—90 mm, outer diameter of the pinion—88.77 mm, and outer diameter of the gear—112.5 mm.
Test gears made of 18CrNiMo7-6 steel of 733 ± 14 HV hardness and made of 35CrMnSiA nanobainitic [20,21,22,23,24] steel of 671 ± 20 HV hardness were used. A coating with the commercial name Balinit C Star (made of W-DLC/CrN coating material) was applied on the gears’ teeth. The company Oerlikon Balzers Coating, Polkowice, Poland conducted the process of coating the teeth’s surfaces using the PACVD technology. The W-DLC/CrN coating applied on 18CrNiMo7-6 steel was 4.8 µm thick, and the coating on 35CrMnSiA steel was 3.8 µm thick.
Coating adhesion was evaluated using scratch adhesion tests conducted with CSM Instruments Revetest equipment (Peseux, Switzerland) with a standard Rockwell C diamond indenter, table speed of 10 mm/min, load increase rate of 100 N/min, and a scratch length of 10 mm. The values of the forces inducing the characteristic mechanisms of coating damage were determined by microscopic observations of the coating damage in the scratched area. The adhesion for the W-DLC/CrN coating on 18CrNiMo7-6 steel was 40 N, while it was 50 N for the coating on 35CrMnSiA steel. The hardness of the W-DLC/CrN coating on 18CrNiMo7-6 steel was 13 GPa; in turn, it was 10 GPa for the coating on 35CrMnSiA steel.
The tribological, component FZG shock scuffing tests were performed following the S-A10/16,6R/90 method described in the FVA No. 243, June 2000 [25,26,27,28,29,30] working paper. The tests were conducted at the T-12UF test stand in the Łukasiewicz—Institute of Sustainable Technologies, Poland [31,32,33].
Each test began with a stable rotational speed and identical initial temperature. As part of the shock scuffing method, the loading is not increased gradually from the lowest value, but the test gears are put under such (“shock”) loading that scuffing is expected straightaway. The maximal loading value is 12, which creates a loading torque of 535 Nm and a Hertzian stress of 2.6 GPa. This approach avoids the gears’ run-in, thereby increasing their susceptibility to scuffing. Tests are conducted until the scuffing criterion is met, which is determined by measuring the area of the pinion’s surface showing wear traces. The criterion is considered fulfilled if damage appears on a surface larger than 100 mm2.
Test conditions:
Motor rotational speed3000 rpm;
Circumferential speed16.6 m/s;
Run duration7 min. 30 s;
Maximum load stage12;
Maximum loading torque535 N·m;
Maximum Hertzian stress2.6 GPa;
Initial lubrication oil temperature90 °C (uncontrolled after starting the run);
Type of lubricationdip lubrication (oil quantity ca. 1.5 dm3).
Shell Omala S4 GX 320 commercial industrial gear oil with PAO (polyalphaolefin) synthetic base of the 6/6 EP AGMA viscosity class was used in the tests. Tribological tests employing the scuffing method under severe conditions were conducted using the S-A10/16,6R/90 method described in the following standard: FVA No. 243, June 2000.

3. Results

The applied microscopy techniques allowed for the observation of wear propagation after shock scuffing tests, with a maximal 12th loading level of the cylindrical toothed gear. The techniques enabled the identification of the type of damage usually present on the pinion tooth’s working surface, a characteristic of scuffing tests (Table 1).
On the basis of microscopic image analysis, the mechanisms of scuffing on the cylindrical gear teeth’s working surfaces were described. The most common damage influencing the surface’s state was observed. The surface damage and wear trace diagrams, along with the images of shock scuffing tests performed at the maximal, 12th, loading level, and of the pinion teeth’s damaged surfaces, are presented in Table 2. By analyzing the images of each tooth’s surface area (2.5 mm × 2.5 mm) with the use of a MM-40 optical microscope from Nikon, Tokyo, Japan, the most frequent types of damage for the given pairings were observed.
Out of all the tested material combinations, the pairing with the pinion of 35CrMnSiA/W-DLC/CrN steel was decidedly the least resistant to scuffing. The wear value of the teeth’s area was Ap = 106 mm2. The damage on the pinion’s surface covered an area of more than 100 mm2. Thus, according to the assessment criterion, the pinion’s working surface was scuffing. Plenty of damage in the form of grooves made by the tooth root (Table 2) was identified microscopically. The pairing with the pinion of the 35CrMnSiA steel was another material pairing for which the wear value of the pinion’s surface was worrying, because it amounted to Ap = 59.0 mm2. There was no scuffing, according to the criterion of its assessment, but the surface’s microscopic analysis demonstrated the presence of micropitting wear forms and noticeable scuffing areas. Scratches and polishings were observed on the working surface of the pinion made of 18CrNiMo7-6/W-DLC/CrN steel. The shock scuffing method allowed for differentiating the analyzed material pairings of the gears.
The results of SEM tests performed with the scanning electron microscope model SU-70 from Hitachi, Tokyo, Japan, integrated with an NSS 312 energy dispersive spectrometer EDS by Thermo Scientific, Waltham, MA, USA, are presented in Figure 2. The SEM images were made of the working surface of the pinion’s teeth before and after shock scuffing tests on an area of 100 µm × 100 µm. The teeth’s working surfaces before the scuffing tests are characterized, in the case of steel, with a texture characteristic of longitudinal grinding. In turn, in the case of the modified surfaces, drops typical for applied PVD coatings were observed. Damage in the form of grooves was observed after the scuffing tests on the surface of a tooth made of 18CrNiMo7-6 steel. On the other hand, break-outs and chippings characteristic of micropitting were identified on the surface of a tooth made of 35CrMnSiA steel.
The elemental decomposition of the working surface of a tooth made of 18CrNiMo7-6 steel with a W-DLC/CrN coating and of 35CrMnSiA steel with a W-DLC/CrN coating before the shock scuffing tests is presented in Figure 3. The map of wolfram decomposition was marked pink. In turn, Figure 4 shows the maps of elemental decomposition after the shock scuffing tests.
The coating on the tooth made of 18CrNiMo7-6 steel, as well as on the tooth made of 35CrMnSiA steel, was partially damaged and worn, which was confirmed by the EDS elemental decomposition analysis, which showed changes in the outer layer’s chemical composition (Figure 4). By analyzing the map of the EDS elemental decomposition on the surface of the tooth made of 18CrNiMo7-6 steel with the W-DLC/CrN coating, after the shock scuffing tests, it was observed that the W-DLC layer was worn through to the CrN interlayer. A different manner of loading the tooth’s working surface produced a vastly different test result for this pairing than observed in the case of scuffing in severe conditions, during which the surface made of 35CrMnSiA steel preserved its coating without showing visible damage [19].
In both cases, the outer layer of the W/DLC coating was damaged, which is confirmed by the lack of wolfram on the EDC elemental decomposition maps (in pink). On the decomposition maps, chromium (marked with yellow) is present on the whole analyzed surface, proving that the CrN layer was not worn. Areas in which the base surface was completely uncovered were also noted. This is confirmed by the presence of iron on the decomposition maps (in red).
The 3D microscopic images of a 20 µm × 20 µm tooth’s working surface generated with an AFM Q-scope 250 atomic force microscope from Quesant Instrument Corporation are shown in Figure 5. The microscope has shown details of the surface formation before and after the shock scuffing tests. The nature of the changes observed on the surface confirmed the characteristics of the changes shown using SEM. Due to running-in, polishing traces were removed from the surface of the tooth made of 18CrNiMo7-6 steel. The surface of the 35CrMnSiA steel/W-DLC/CrN tooth was damaged, numerous pits were observed, and grooves perpendicular to the polishing direction appeared. The surface of the tooth made of 35CrMnSiA steel behaved similarly. In the case of the 18CrNiMo7-6 steel/W-DLC-CrN tooth, the steel base surface with some traces of polishing is visible after the coating’s removal.
The images of the 1600 µm × 1600 µm working surface of the pinion, made with WLI interferometric microscope produced by Taylor Hobson, are presented in Figure 6 and Figure 7. Figure 6 shows a 3D microscale view of the pinion’s working surface before the scuffing tests, while Figure 7 shows 3D microscale images after scuffing tests. The state of the measured surface was described, with the vertical dimensions of the tested surface marked with the following symbols: Sp—maximal rising height, Sv—maximal pit depth, Sz—maximal surface elevation, Sa—arithmetic average surface roughness deviation, and Sq—root mean square surface roughness deviation.
The use of the interferometric microscope in the working surface testing of the pinion’s tooth allowed for presenting the surface spatially as well as for a quantitative analysis of qualities of the tested area’s formation. It was observed that the surface of the tooth made of 18CrNiMo7-6 steel after the scuffing tests was characterized by the lowest values of all the analyzed roughness parameters. In turn, the highest value of the Sz parameter, above 10.0 µm, was noted in the case of the coated surfaces, both for 18CrNiMo7-6 steel and 35CrMnSiA steel. The highest Sv value of 7.043 µm was present in 35CrMnSiA steel with a coating. This points to considerable surface damage compared to the state of the surface before the tribological tests. In the case of the working surface of the 35CrMnSiA steel tooth, pits described with the Sv parameter of 4.047 µm were observed, which suggests the damage of the tooth’s working surface.
The presented images obtained using an optical microscope, a scanning electron microscope, and an atomic force microscope enabled qualitative analysis of the tested surface at a wide scale from macro to nano.
The surface was analyzed using the following:
  • A SU-70 field-emission scanning electron microscope (FE-SEM), produced by Hitachi, Tokyo, Japan, integrated with an NSS 312 energy dispersive spectrometer (EDS) produced by Thermo Scientific, Madison, WI, USA, for surface imaging in microscale and elemental analysis (acceleration voltage of 15 kV, take-off angle of 30, vacuum conditions 1 × 10−8 Pa, a secondary electron (SE) detector, and magnification for images-1000× for the elemental composition maps were acquired at 3000× magnification);
  • A WLI optical profilometer, produced by Taylor Hobson, Leicester, UK, for 3D surface imaging at the micro scale and the measurement of surface roughness (10× magnification). The microscope is equipped with a set of Mirou objectives (5×, 10×, 20×, and 50×) and a CCD camera used for measurement data acquisition. The analysis of the measured dimensions is carried out using TalyMap v.7 software;
  • A Q-scope 250 atomic force microscope (AFM) produced by the Quesant Instrument Corporation, Agoura Hills, CA, USA, for 3D surface imaging at the nano scale (contact mode measurement, and measurement head of the microscope: 20 × 20 μm);
  • A MM-40 optical microscope produced by Nikon, Tokyo, Japan (50× magnification), equipped with the MultiScanBase v.8 system for image acquisition and digital processing, as well as a set of objectives with magnifications of 5×, 10×, 20×, and 50×.

4. Conclusions

Tests conducted at the maximal, 12th stage of shock loading allowed for the assessment of the effectiveness of used materials and protective coatings when it comes to resistance to scuffing. The following conclusions were reached after a microscopic analysis of the pinion tooth’s working surface:
  • The 35CrMnSiA steel pinions with W-DLC/CrN coating were scuffing under shock loading. The coating proved insufficient under extreme overloading conditions.
  • Scuffing areas were observed on the surface of the 35CrMnSiA steel tooth.
  • The 18CrNiMo7-6 steel pinions without the coating were not scuffing even under the highest, 12th, stage of loading. This proves this steel has a much higher material resistance to scuffing compared with 35CrMnSiA steel.
  • The surfaces of 18CrNiMo7-6 steel gear teeth, coated with DLC/CrN, showed no signs of scuffing even under maximum loading. The combination of a high-quality base material and the coating proved effective under shock scuffing conditions.
The effect of the type of loading on the resistance to scuffing was deemed important based on the microscopic observations (SEM, AFM, WLI, and optical microscopy) of the 35CrMnSiA steel pinion teeth’s working surfaces coated with W-DLC/CrN. A lower resistance to scuffing was observed under shock loading, which corresponds to operation in industrial settings, than in tests under severe conditions [19]. The working surfaces of the teeth were damaged and exhibited scuffing despite the application of a coating. This suggests that the W-DLC/CrN coating efficiency under shock loading conditions may be limited and requires further optimalisation when it comes to both the layer structure and mechanical qualities of the coating and its adhesion to the base surface.

Author Contributions

Conceptualization, E.O.-S.; methodology, E.O.-S.; formal analysis, E.O.-S., A.N.W. and R.M.; investigation, E.O.-S., M.G., A.M.-S. and E.S.; writing—original draft preparation, E.O.-S.; writing—review and editing, R.M. and A.N.W.; visualization, E.O.-S.; supervision, R.M. and A.N.W.; project administration, A.N.W.; and funding acquisition A.N.W. All authors have read and agreed to the published version of the manuscript.

Funding

The study was carried out as part of two projects financed by the National Centre for Research and Development, Poland: “Development of innovative hybrid surface layers composed of anti-wear coatings dedicated to gears for conveyor drive assemblies working in difficult operating conditions”. No. TECHMATSTRATEG-III/0028/2019 and “Development of an innovative technology for the manufacture of toothed components with hybrid surface layers with a nanostructure base for the drive units of conveyors designed to be used in extreme operating conditions”. No. POIR.04.01.04-00-0064/15.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The data presented in this study are available on request from the corresponding author. The data is not publicly available due to the fact that information regarding the transmission technology is reserved by the manufacturer.

Conflicts of Interest

The authors declare no conflicts of interest.

Abbreviations

The following abbreviations are used in this manuscript:
FLSfailure load stage
FZGthe Gear Research Centre (Forschungsstelle fur Zahnrader und Getriebebau, FZG) of the Technical University of Munich
DLCDiamond-like Carbon coating
SEMScanning Electron Microscope
EDSEnergy Dispersive Spectrometer
WLIWhite Light Interferometer Microscope
AFMAtomic Force Microscope
Raprofile roughness [µm]
Sasurface roughness [µm]
Spmaximum peak height [µm]
Svmaximum indentation depth [µm]
Szmaximum surface height [µm]
Sqmean square deviation of the surface roughness [µm]
Apwear surface area of the small gear teeth [mm2]

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Figure 1. Test FZG gear pair, type A10, the pinion coated with W-DLC/CrN.
Figure 1. Test FZG gear pair, type A10, the pinion coated with W-DLC/CrN.
Coatings 15 00857 g001
Figure 2. The SEM images of the tooth’s working surface made before and after the shock scuffing tests.
Figure 2. The SEM images of the tooth’s working surface made before and after the shock scuffing tests.
Coatings 15 00857 g002aCoatings 15 00857 g002b
Figure 3. The SEM images and maps of EDS elemental decomposition of the working surface of a tooth made of 18CrNiMo7-6 steel and coating and 35CrMnSiA steel and coating, made before the shock scuffing tests (1500× magnification).
Figure 3. The SEM images and maps of EDS elemental decomposition of the working surface of a tooth made of 18CrNiMo7-6 steel and coating and 35CrMnSiA steel and coating, made before the shock scuffing tests (1500× magnification).
Coatings 15 00857 g003aCoatings 15 00857 g003b
Figure 4. The SEM images and maps of EDS elemental decomposition of the working surface of a tooth made of 18CrNiMo7-6 steel and coating and of 35CrMnSiA steel and coating, produced after the shock scuffing tests (1500× magnification).
Figure 4. The SEM images and maps of EDS elemental decomposition of the working surface of a tooth made of 18CrNiMo7-6 steel and coating and of 35CrMnSiA steel and coating, produced after the shock scuffing tests (1500× magnification).
Coatings 15 00857 g004
Figure 5. The test results of formation of tooth’s working surface before and after the AFM shock scuffing tests.
Figure 5. The test results of formation of tooth’s working surface before and after the AFM shock scuffing tests.
Coatings 15 00857 g005aCoatings 15 00857 g005b
Figure 6. The interferometric microscope test results of tooth’s working surface formation (3D view) before the shock scuffing tests.
Figure 6. The interferometric microscope test results of tooth’s working surface formation (3D view) before the shock scuffing tests.
Coatings 15 00857 g006
Figure 7. The interferometric microscope test results of tooth’s working surface formation (3D view) after the shock scuffing tests.
Figure 7. The interferometric microscope test results of tooth’s working surface formation (3D view) after the shock scuffing tests.
Coatings 15 00857 g007
Table 1. The type of damage present on teeth’s working surfaces after scuffing tests.
Table 1. The type of damage present on teeth’s working surfaces after scuffing tests.
PolishingScratchesScoringScuffing
Coatings 15 00857 i001Coatings 15 00857 i002Coatings 15 00857 i003Coatings 15 00857 i004
Table 2. The gear tooth’s working surface after shock scuffing, maximally at the 12th stage of failure load.
Table 2. The gear tooth’s working surface after shock scuffing, maximally at the 12th stage of failure load.
Pinion MaterialThe Working Surface of the Pinion Gear After Scuffing Tests Under Shock Conditions
Test GearModes of the Wear of the Test Pinion at Maximum Load Stage with the Total Area of Failures on the PinionWorking Surface
of the Pinion Tooth
Optical Microscope Image
17HNM steelCoatings 15 00857 i005Coatings 15 00857 i006
Ap ≈ 32.0 mm2
Coatings 15 00857 i007Coatings 15 00857 i008
17HNM/
W-DLC/CrN coating
Coatings 15 00857 i009Coatings 15 00857 i010
Ap ≈ 7.0 mm2
Coatings 15 00857 i011Coatings 15 00857 i012
35HGSA steelCoatings 15 00857 i013Coatings 15 00857 i014
Ap ≈ 59.0 mm2
Coatings 15 00857 i015Coatings 15 00857 i016
35HGSA/
W-DLC/CrN coating
Coatings 15 00857 i017Coatings 15 00857 i018
Ap ≈ 106.0 mm2
Coatings 15 00857 i019Coatings 15 00857 i020
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MDPI and ACS Style

Osuch-Słomka, E.; Michalczewski, R.; Mańkowska-Snopczyńska, A.; Gibała, M.; Wieczorek, A.N.; Skołek, E. Influence of Gear Set Loading on Surface Damage Forms for Gear Teeth with DLC Coating. Coatings 2025, 15, 857. https://doi.org/10.3390/coatings15070857

AMA Style

Osuch-Słomka E, Michalczewski R, Mańkowska-Snopczyńska A, Gibała M, Wieczorek AN, Skołek E. Influence of Gear Set Loading on Surface Damage Forms for Gear Teeth with DLC Coating. Coatings. 2025; 15(7):857. https://doi.org/10.3390/coatings15070857

Chicago/Turabian Style

Osuch-Słomka, Edyta, Remigiusz Michalczewski, Anita Mańkowska-Snopczyńska, Michał Gibała, Andrzej N. Wieczorek, and Emilia Skołek. 2025. "Influence of Gear Set Loading on Surface Damage Forms for Gear Teeth with DLC Coating" Coatings 15, no. 7: 857. https://doi.org/10.3390/coatings15070857

APA Style

Osuch-Słomka, E., Michalczewski, R., Mańkowska-Snopczyńska, A., Gibała, M., Wieczorek, A. N., & Skołek, E. (2025). Influence of Gear Set Loading on Surface Damage Forms for Gear Teeth with DLC Coating. Coatings, 15(7), 857. https://doi.org/10.3390/coatings15070857

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