Analyse of Tribological Properties of Layers Created by Plasma Nitriding + DLC

Dobrocký, David; Pokorny, Zdenek; Studeny, Zbynek; Doan, Thanh Van

doi:10.21062/ujep/109.2018/a/1213-2489/mt/18/3/379

Cited by 3 publications

(2 citation statements)

References 15 publications

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“…The DLC designation is used for the metastable amorphous carbon state [10]. Although DLC coating have a graphite-like structure, they are characterized by lower hardness and abrasion resistance at low friction coefficients (0.15) [11]. Nitrogen is used to improve adhesion to the substrate.…”

Section: Methodsmentioning

confidence: 99%

The Application of DLC Coating on Convex-concave (C-C) Gearings

Gondár¹,

Bošanský²,

Rusnák³

et al. 2019

Manufacturing Technology

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This paper discusses the possibility of increasing the surface load capacity in C60E steel gearings by applying DLC thin coating. It describes the effect of tribological characteristics, such as friction coefficient, wear, adhesion and hardness of DLC coating on convex-concave gearing (C-C). The average thickness of DLC coating is 1.2 μm. Delamination of the DLC coating was recorded at a load of approximately 50 N. The friction coefficient of the DLC coating was 0.09. The nano-hardness of the DLC coating was 14.4 GPa. The results of the tests to scuffing on C-C gearings on the Niemann tester show that the DLC coating deposition occurred at load level 5. The complete removal of the coating was preceded by gradual thinning. After its removal, the wear continued substrate, where the traces after milling filled-up with the substrate metal.

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Section: Methodsmentioning

confidence: 99%

The Application of DLC Coating on Convex-concave (C-C) Gearings

Gondár¹,

Bošanský²,

Rusnák³

et al. 2019

Manufacturing Technology

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“…Methods such as surface hardening and carburizing are based on steel quenching from high temperatures (above critical temperature), whereby residual stress and geometrical deformations in the surface of the resulting products may occur. In case of nitriding, the temperature is significantly lower, generally in range of 490-560 • C, thereby a higher accuracy of product geometry can be achieved, and thus it can be also used in a combination of surface treatments called a duplex [8][9][10][11]. Moreover, nitriding is applicable for treating the outer surfaces of highly exposed parts of military technology as well as for the inner surfaces of barrel bores of small arms, where parameters such as resistance to wear and hardness are essential as well as in the case of cutting tools [12,13].…”

Section: Introductionmentioning

confidence: 99%

Service Behavior of Nitride Layers of Steels for Military Applications

2020

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Steels which are utilized in the manufacturing of specific parts of military technology such as crankshafts of engines in heavy-duty vehicles or barrels of guns must be subsequently modified by heat treatment according to the requirements of customers. Despite the hard surface of martensitic structure obtained by hardening process, steels have a low wear resistance and high values of coefficient of friction. To improve these parameters and due to the fact that many of steels which are utilized for manufacturing of mentioned parts are also categorized as Nitralloy steels, in this paper, the improvement in these properties of chosen steels by the application of plasma nitriding has been studied. The steel equivalent 17Ni4CrMo (i.e., CSN 41 6720) and equivalent 42CrMo4 (i.e., CSN 41 5142) were chosen for the study. The chemical composition of chosen steels was verified by optical emission spectrometry. The microstructure and the diffusion layer were observed by optical microscopy due to the evaluation of layer parameters important for the lifetime. ZWICK ZHU 2.5 was used for a measurement of the universal hardness of the surface and values of graphs of microhardness were obtained by the device LM 247AT LECO from a cross-section of samples. The coefficient of friction was determined by Bruker CERT-UMT-3 with a ball-on-disc method. The parameters of wear paths were obtained by Talysurf CLI 1000. After the application of plasma nitriding technology, the hardness of both steels was rapidly increased in comparison with non-nitrided samples. According to the comparison of coefficients of friction with respect to the parameters of the measurement, the coefficient of friction of nitrided samples decreases with increasing temperature, which is essential knowledge for the weapon industry, especially the construction of bore barrel.

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Wear Behaviour of High Strength Tool Steel 90MnCrV8 in Contact with Si3N4

Krbaťa

Eckert

Majerík

et al. 2020

Metals

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Tool steels are used in technological processes of forming and cutting and as cutting tools due to their good mechanical properties. During their working cycle, steels are exposed to several aggressive conditions, such as thermal stress, fatigue and various forms of wear. In this article, the selected 90MnCrV8 tool steel slid against the Si3N4 testing ceramic bearing ball. All measurements were performed on a universal tribometric device UMT TriboLab (TA Instruments, New Castle, Delaware, USA) under dry conditions. The main objective of the performed experiments was to analyse the frictional properties and compare the wear of the 90MnCrV8 tested tool steel in contact with the 6.35 mm diameter ceramic ball at different friction speeds. In this measurement evaluation, the authors of the article mainly focused on the influence of the magnitude of the peripheral speed on the wear change and coefficient of friction. Further analysis was focused on the change of surface roughness of the counterpart ceramic balls as well as of the tested tool steel samples. Experimental results show the fact that tested tool steels, which can also be considered as high strength steels, can also successfully represent wear-resistant steels. It has been shown experimentally that increasing the friction speed also leads to significant degradation of the material on the sample surface. Finally, the effect of hardness on wear has also been experimentally demonstrated. The Si3N4 ceramic ball with its high strength also behaves like an abrasive, thus increasing the wear rate on the experimental tool steel samples.

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Analyse of Tribological Properties of Layers Created by Plasma Nitriding + DLC

Cited by 3 publications

References 15 publications

The Application of DLC Coating on Convex-concave (C-C) Gearings

The Application of DLC Coating on Convex-concave (C-C) Gearings

Service Behavior of Nitride Layers of Steels for Military Applications

Wear Behaviour of High Strength Tool Steel 90MnCrV8 in Contact with Si3N4

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