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1

Carbon based coatings for applications in friction couples with bearing steel and aluminium alloy

Makówka M., Wendler B.

Archives of Materials Science and Engineering

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2017

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Vol. 87, nr 1

12--20

EN

Purpose: Low friction nc-WC/a-C:H coatings deposited by means of magnetron sputtering provide very good tribological properties in friction couple against hard steels and good adhesion to steel substrates. Nevertheless, it was necessary to elaborate a new type of coatings because the nc-WC/a-C:H one had no use in friction couple against aluminium alloys. Design/methodology/approach: In the paper the WC/a-C:H and (Si, Cr)C/a-C:H coatings were investigated. The coatings were investigated by means of SEM, EDS, in order to obtain thickness, surface morphology and chemical composition of coatings. Tribological properties of deposited coatings were elaborated by means of 'pin-on-disc' method in friction couple against 100Cr6 bearing steel and AlSi alloy. Findings: It was stated that (Si, Cr)C/a-C:H coatings have very good tribological properties in friction couple against bearing steel and AlSi alloy (friction coefficient <0,1). In case of WC/a-C:H coatings, good tribological properties were achieved in friction couple with bearing steel. Both coatings have very low wear rate in investigated friction couples. Research limitations/implications: The (Si,Cr)C/a-C:H coating have a worse quality of adhesion to quenched and tempered Vanadis 23 HS steel substrate in comparison with the nc-WC/a-C:H coating. Resolving this disadvantage can increase potential of application of (Si, Cr)C/a-C:H coatings. Practical implications: Newly developed (Si, Cr)C/a-C:H coating has a greater application potential for modification of surfaces of elements working in friction couples against hardened steels and light alloys like AlSi. Originality/value: There are numerous publications where low friction carbon based coatings were described mostly as a coatings deposited on elements working in friction couples against hard steels. Undertaken tests showed that the newly developed (Si,Cr)C/aC:H coating can have a broad spectrum of applications in friction couples against different counterbodies, including light Al alloys.

2

Study of CVD diamond layers with amorphous carbon admixture by Raman scattering spectroscopy

Dychalska A., Popielarski P., Franków W., Fabisiak K., Paprocki K., Szybowicz M.

Materials Science Poland

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2015

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Vol. 33, No. 4

799--805

EN

Raman spectroscopy is a most often used standard technique for characterization of different carbon materials. In this work we present the Raman spectra of polycrystalline diamond layers of different quality, synthesized by Hot Filament Chemical Vapor Deposition method (HF CVD). We show how to use Raman spectroscopy for the analysis of the Raman bands to determine the structure of diamond films as well as the structure of amorphous carbon admixture. Raman spectroscopy has become an important technique for the analysis of CVD diamond films. The first-order diamond Raman peak at ca. 1332 cm−1 is an unambiguous evidence for the presence of diamond phase in the deposited layer. However, the existence of non-diamond carbon components in a CVD diamond layer produces several overlapping peaks in the same wavenumber region as the first order diamond peak. The intensities, wavenumber, full width at half maximum (FWHM) of these bands are dependent on quality of diamond layer which is dependent on the deposition conditions. The aim of the present work is to relate the features of diamond Raman spectra to the features of Raman spectra of non-diamond phase admixture and occurrence of other carbon structures in the obtained diamond thin films.

3

Analizatory do oznaczania frakcji węgla wielopostaciowego w materiałach węglopochodnych, w tym kompozytowych

Witowski A.

Elektronika : konstrukcje, technologie, zastosowania

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2009

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Vol. 50, nr 7

154-157

PL

W artykule omówiono aktualnie prowadzone w Instytucie Tele- i Radiotechnicznym prace nad opracowaniem rodziny analizatorów do oznaczania frakcji węgla wielopostaciowego w materiałach węglopochodnych. Omawiane analizatory są nowymi rozwiązaniami technicznymi wykorzystującymi unikalną metodę pomiarową, polegającą na selektywnym utlenianiu zawartego w badanym materiale węgla wielopostaciowego i określaniu zawartości jego poszczególnych frakcji za pomocą modułów detekcyjnych NDIR. Proces oznaczania wielopostaciowych odmian węgla jest w pełni zautomatyzowany i sterowany komputerowo.

EN

Current work, carried out in the Tele & Radio Research Institute, on the elaboration of the analysers for determination of polymorphic carbon fractions in carbonic materials has been described. In the presented analysers new design solutions, based on an unique method of measurements, have been used. The method consists in selective oxidation of a polymorphic carbon included in the investigated material to determine a content of various kinds of carbon by NDIR detecting modules. The process of determination of various forms of carbon is fully automatized and computer controlled.

4

Morphological forms of carbon and their utilizations at formation of iron casting surfaces

Jelinek P., Beňo J.

Archives of Foundry Engineering

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2008

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Vol. 8, iss. 2

67-70

EN

Model pyrolysis made possible to identify three solid products of carbonaceous additives. Lustrous carbon is the most important form of the pyrolysis carbon. With its structure and physical and chemical properties it comes near to graphite. Amorphous carbon with turbo-stratic lattice, higher oxireactivity, and lower protective function against liquid metal comes near to carbon black. Semicoke also plays a non-negligible role. All forms of carbon have an important representation in oolitized quartz grain also during forming the casting surface. While amorphous carbon is formed directly from the gaseous phase by homogeneous nucleation, lustrous carbon, with regard to similarity of lattices with quartz, is formed by heterogeneous nucleation on grains. High covering power and low oxireactivity give its highest protecting power of the mould face. New experimental equipment made possible to check a possibility of use of new composite bentonite binders containing "process carbon" (graphite, anthracite, amorphous carbon). The BTEX content in exhalations and in waste sands too was considerably decreased with high smoothness of castings.

5

Pomiar zawartości węgla błyszczącego w materiałach stosowanych jako zamienniki pyłu węglowego w masach formierskich

Witowski A.

Elektronika : konstrukcje, technologie, zastosowania

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2006

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Vol. 47, nr 7

66-68

PL

Omówiono wpływ węgla błyszczącego na jakość odlewów, metody jego oznaczania, w tym opracowany w PIE model analizatora do oznaczania węgla błyszczącego w zamiennikach pyłu węglowego oraz w masach formierskich.

EN

In this paper, the importance of the pyrolytical carbon in the foundry process as well as the review of the analitycal methods for determination of the lustrous carbon are presented. The new methodology as well as equipment enables the direct determination of lustrous carbon in coal carriers is also presented.The analyzer is suitable for controlling the quality of carriers of lustrous carbon.

6

Nanoszenie cienkich warstw węgla amorficznego za pomocą elektrolizy metanolu i etanolu na podłoże krzemu

Szatkowski J.

Karbo

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2002

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Nr 10

284-286

PL

Zaprezentowano wyniki pomiarów spektroskopii Ramana i elektronowej mikroskopii skaningowej warstw węgla amorficznego otrzymanego metodą elektrolizy ciekłego metanolu i etanolu na podłożu krzemowym. Z pomiarów tych wynika, że otrzymane warstwy węgla amorficznego charakteryzują się obszarami, w których występują atomy węgla o hy-brydyzacji sp(3), o czym świadczy sygnał w widmie Ramana w okolicy 1332 cm(-1).

EN

Results of measurements have been presented of Raman spectroscopy and SEM of thin films of amorphous carbon produced by electrolysis methanol and ethanol on silicone substrates. It can be seen from results, that in thin films of amorphous carbon make-up characterisation of including regions with sp(3) hybridisation of carbon atoms. The evidence of this is signal of Raman spectroscopy near 1332 cm(-1).