Wyniki wyszukiwania - BazTech

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Characterization of oxide layers formed on 10CrMo9-10 steel operated for a long time in the power industry

Gwoździk Monika, Ullrich Christiane, Schimpf Christian, Rafaja David, Kulesza Sławomir, Bramowicz Mirosław

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 4

art. no. e137730

EN

This paper presents the results of diagnostic examinations conducted on the coils of super-heaters made of 10CrMo9‒10 steel that were operated in industrial conditions at 480°C for 130 thousand hours. The tube was exposed in a coal-fired boiler. The chemical and phase composition of the oxide/deposit layers formed on both sides of the tube walls (outside – flue-gas side and inside – steam side) and their sequence was examined using optical microscopy, scanning electron microscopy with electron backscatter diffraction and energy-dispersive X-ray spectroscopy, and X-ray diffraction. The changes in the mechanical properties caused by corrosion and aging processes were concluded from the hardness measurements. In addition, the nature of cracks in the oxide layers caused by pressing a Vickers indenter was determined. The results of these examinations have shown a high degradation of steel on the flue-gas inflow side and identified the main corrosion products and mechanisms.

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Atomic force microscopy with fractal studies of temperature induced changes in the surface topography of polymeric materials

Rydzkowski Tomasz, Kulesza Sławomir, Bramowicz Mirosław, Michalska-Pożoga Iwona

Polimery

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2020

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T. 65, nr 1

25--32

EN

Changes in the surface topography of polymeric materials can be analyzed to find the correspondence between observed surface features and specific external factors that might also influence physical and functional properties of the investigated material. In this work, atomic force microscopy (AFM) measurements were carried out to investigate the thermal changes in the surface topography as well as in the inner structure of the low density polyethylene (LDPE) samples subjected to 10 recirculations (rLDPE). For better assessment, fractal analysis and AFM results were additionally compared to DSC tests results.

PL

Analiza zmian topografii powierzchni materiałów polimerowych pozwala wyznaczyć zależności między obserwowanymi cechami powierzchni a określonymi czynnikami zewnętrznymi, które mogą wpływać na właściwości fizyczne i funkcjonalne badanego materiału. W niniejszej pracy metodą mikroskopii sił atomowych (AFM) oceniano zmiany termiczne topografii powierzchni, a także wewnętrznej struktury próbek polietylenu małej gęstości (LDPE) poddanych 10-krotnej recyrkulacji (rLDPE). Wyniki AFM i analizy fraktalnej porównywano z wynikami badań metodą różnicowej kalorymetrii skaningowej (DSC).

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Influence of gas detonation spraying parameters on the geometrical structure of Fe-Al intermetallic protective coatings

Chrostek Tomasz, Bramowicz Mirosław, Rychlik Kazimierz, Wojtkowiak Adam, Senderowski Cezary

Technical Sciences / University of Warmia and Mazury in Olsztyn

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2019

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nr 22(3)

249--262

EN

The paper presents the results of an analysis of the geometrical structure of Fe-Al intermetallic protective coatings sprayed under specified gun detonation spraying (GDS) conditions. Two barrel lengths, two powder injection positions (PIP) at the moment of spark detonation, and two numbers of GDS shots with 6.66 Hz frequency were applied as variable parameters in the GDS process. Surface profile measurements were conducted by contact profilometry with the use of the TOPO-01 system and the Mitutoyo SJ 210 profilometer. The measured parameters were used to analyze surface topography in two-dimensional (2D) and three-dimensional (3D) systems. It was assumed that roughness can be regarded as a non-stationary parameter of variance in surface amplitude which is highly dependent on the sampling rate and spraying distance. Therefore, changes in surface amplitude parameters and functional properties were analyzed across segments with a length (ln) of 1.25, 4 and 12.5 mm. The development of the geometric structure of the surface was analyzed with the RMS (Root Mean Square) fractal method, and the geometric structure of the surface stretched by several orders of magnitude was evaluated based on the correlation between roughness (Rq), segment length (ln) and fractal dimension (D). The RMS method and the calculated fractal dimension (D) supported the characterization of the geometric structure of intermetallic Fe-Al protective coatings subjected to GDS under the specified process conditions based on the roughness profiles of surface segments with a different length (ln).

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Wpływ rozdzielczości skanowania mikroskopu AFM na wyznaczone wartości geometryczne, fraktalne i statystyczne

Bramowicz Mirosław, Kulesza Sławomir, Szabracki Paweł, Lipiński Tomasz

Inżynieria Materiałowa

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2013

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Vol. 34, nr 1

50--55

PL

W pracy przedstawiono wyniki analizy wpływu rozdzielczości skanowania mikroskopu AFM na parametry geometryczne, charakterystyczne dla badanej wzorcowej powierzchni, oraz parametry statystyczne i fraktalne. W pracy opisano serię pomiarów topografii wzorca TGT1 (NT-MDT) przy różnej rozdzielczości skanowania w kontaktowym trybie pracy mikroskopu AFM. Wartości parametrów statystycznych: Sa, Sq, Sy, wyznaczone dla różnych rozdzielczości skanowania zgodnie z normą ISO 25178-6, porównano ze sobą oraz zestawiono z parametrami fraktalnymi: długością korelacji (rc), wymiarem fraktalnym (D) oraz topotezą powierzchni (K). Z przeprowadzonych pomiarów wynika, że w przypadku okresowego ukształtowania powierzchni krok pomiarowy (w analizowanym zakresie) nie wywiera istotnego wpływu na wartości parametrów geometrycznych, statystycznych oraz ocenę anizotropii powierzchni. Jego wartość, jak i gęstość skanowania są istotne w analizie fraktalnej przeprowadzanej metodą funkcji struktury S(t). Wynika to ze wzrastającej wraz z rozdzielczością liczby punktów mieszczących się w liniowym zakresie krzywej S(t) wyznaczającym obszar samopodobieństwa badanej powierzchni.

EN

The effect of the scanning resolution on the geometrical, statistical and fractal parameters extracted from the AFM images of the reference sample of a well-known shape is analyzed in the paper. A series of measurements was carried out in the contact mode on the TGT1 calibration grating supplied by NT-MDT. The statistical parameters Sa, Sq, Sy were estimated (according to norm ISO 25178-6) and compared to the images with different scan resolution, and then the numerical procedure was applied to extract fractal parameters such as: the correlation length (rc), fractal dimension (D) and topothesy (K) from the AFM images of different lateral resolution. The obtained results suggest that for isotropic surfaces neither geometrical features, statistical features nor the anisotropy ratio is signiﬁcantly affected by the scan step. On the other hand, the scan step and the scan resolution are important when the images are analyzed on the grounds of fractal geometry using the structure function S(t). This is mainly due to the fact that with an increasing scan resolution, the number of points in the linear range of the structure function increases as well, and only within this range does the surface reveal self-afﬁne properties.