Wyniki wyszukiwania - BazTech

1

Zastosowanie metod uczenia maszynowego w analizie obrazu mikroskopowego płytek ceramicznych

Gąsiński Arkadiusz, Tymowicz-Grzyb Paulina

Szkło i Ceramika

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2022

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R. 73, nr 2

34--37

PL

Współczesne metody badań stosowane w nowoczesnych technikach badawczych spowodowały, że zbierane są ogromne ilości danych, które muszą być poddane dalszej analizie. Uczenie maszynowe pomaga interpretować zgromadzone dane, a po ich przetworzeniu może pomóc podjąć dalsze decyzje. Metoda ta ma coraz większe zastosowanie w kontroli jakości wyrobów. W artykule przedstawiono zastosowanie nadzorowanej wersji uczenia maszynowego w badaniach nad optymalizacją rozpoznawania faz chemicznych z obrazów mikroskopowych i obrazów składu chemicznego dla płytek ceramicznych. Stwierdzono, że w przypadku opracowanych danych z elektronowej mikroskopii skaningowej, najlepsze wyniki uzyskano dla algorytmu CART (drzewo decyzyjne). Zastosowana metodyka znacznie usprawnia przeprowadzenie badań i poprawia jakość uzyskanych analiz obrazu w odniesieniu do standardowego oprogramowania mikroskopów.

EN

Contemporary research methods used in modern research techniques often result in the collection of huge amounts of data that must be further analyzed. Machine learning helps to interpret the collected data, and after their processing, it can help you make further decisions. The article presents the use of the supervised machine learning in research on the optimization of the recognition of chemical phases from microscopic images and chemical composition images for ceramic tiles. It was found that in the case of the developed data from scanning electron microscopy, the best results were obtained for the CART algorithm (decision tree structure). The applied methodology significantly improve the conduct of research and ameliorate the quality of the obtained image analyzes.

2

Effect of annealing on the microstructure and properties of IN 625 specimens manufactured by selective laser melting

Sitek Ryszard, Ciftci Jakub, Moszczyńska Dorota, Maj Piotr, Ura-Bińczyk Ewa, Warzybok Piotr, Cieślik Iwona, Wiśniewski Paweł, Mizera Jarosław

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 4

art. no. e207, 2022

EN

The study examines the effect of the annealing on the microstructure, tensile strength (small flat dog-bone specimen size with 5 mm dimension of measuring base) and corrosion resistance of IN 625 nickel superalloy specimens manufactured by means of selective laser melting method (SLM). The annealing of such specimens was carried out in a chamber furnace in a protective atmosphere of argon at a temperature of 1038 °C for 1 h. The cooling process was carried out in an atmosphere of air at ambient temperature. The microstructure of the IN 625 nickel superalloy after the 3D printing process and after the post-process heat treatment (HT) was examined by means of scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). The results showed a uniform microstructure after the SLM process with element microsegregation. The cooling rate in the heat treatment was not sufficient which caused precipitation at the grain boundaries, most probably carbides and resulted in only a partial increase in ductility much lower than that of the material in initial state despite the high temperature applied during the annealing. The strength in the HT was on a level comparable to as-build state, 852 MPa and 891 MPa, respectively. Additional corrosion resistance tests were performed by the potentiodynamic method in a 3.5% NaCl solution at room temperature. HT increased the current density variation from ipass due to the formed precipitates. Our studies show that the size effect is an important factor when assessing the properties of IN 625 obtained using SLM. Despite similar microstructure, the structure defects play a more significant role which translates into lower mechanical properties than in normal sized specimens defined by the standard ASTM E8.

3

Impaktor kaskadowy jako metoda poboru nanoobiektów do analizy mikroskopowej

Kozikowski Paweł, Sobiech Piotr, Oberbek Przemysław, Jakubiak Szymon

Podstawy i Metody Oceny Środowiska Pracy

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2021

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Nr 2 (108)

155--167

PL

Pył zawieszony może być szkodliwy dla zdrowia ludzkiego, a ryzyko wystąpienia szkodliwych skutków zwiększa się z czasem narażenia. Obecnie grupami zawodowymi potencjalnie narażonymi na działanie nanomateriałów są ci, którzy je wytwarzają i dostarczają. Dlatego konieczne jest stosowanie urządzeń do zbierania i analizy cząstek stałych z wyłączeniem frakcji mikrometrycznej. W pracach badawczych pobierano cząstki zawarte w spalinach z silnika wysokoprężnego przy użyciu impaktora kaskadowego i analizowano z zastosowaniem skaningowej mikroskopii elektronowej. Obserwacje ujawniły duże rozbieżności między średnicami odcięcia d50 a średnicami ekwiwalentnymi obliczonymi na podstawie obrazów SEM, a także różnorodną morfologię zdeponowanych cząstek stałych pochodzących z silnika Diesla. Zakres tematyczny artykułu obejmuje zagadnienia zdrowia oraz bezpieczeństwa i higieny środowiska pracy będące przedmiotem badań z zakresu nauk o zdrowiu oraz inżynierii środowiska.

EN

Particulate matter can be harmful to human health and the risk of harmful effects increases with the duration of exposure. Currently, the occupational groups that are potentially exposed to nanomaterials are those who manufacture and supply them. Therefore, it is necessary to use devices for the collection and analysis of solid particles with the exclusion of the ambient fraction. In this study, Diesel soot generated using Diesel engine has been collected with cascade impactor and analyzed by means of scanning electron microscopy. Observations revealed large discrepancies between the cut off diameter d50 and equivalent diameter calculated from SEM images and a number of types of Diesel particulate matter. This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

4

Mechanical and morphological characterization of discarded fishnet/glass fiber reinforced polyester composite

Monivarman P., Nagarajan V. A., Raj F. M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2020

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Vol. 68, nr 6

1385--1391

EN

The present work focuses on the fabrication of glass fiber and multifilament discarded fishnet nylon fiber polymer composites with four different fiber compositions. Composites are molded by means of simple hand lay-up methodology with dissimilar layers of the fiber mat. The mechanical characterization (tensile and impact) and thermal analysis of composites have to be investigated. Among the different patterns, hybrid composites reflected better tensile and impact properties as compared to the conventional materials. Morphological characterization was carried out to figure out the de-bonding of fiber/matrix adhesion characteristics of fractured face of tensile testing samples. The result suggests the potential for reuse of discarded fishnet, which constitutes a better alternative for structural work and for possible applications to be used to develop added-value products.

5

Micro-analytical studies of discontinuous precipitation in Fe-13.5 at.% Zn alloy

Zięba Paweł, Chronowski Mateusz, Morgiel Jerzy

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 3

190--196

EN

For the first time, the analytical electron microscopy has been used to determine the solute concentration profiles left behind the moving reaction front (RF) of the discontinuous precipitation (DP) reaction in a Fe-13.5 at.% Zn alloy. These profiles have been converted into grain boundary diffusivity (sδDb) values, using Cahn’s diffusion equation in its original form and the data of the growth rate of the discontinuous precipitates obtained from independent measurements. This approach has essentially removed existing difference in comparison to sδDb values obtained from Cahn′s simplified and Petermann–Hornbogen models relevant for the global approach to the DP. Simultaneously, the local values of sδDb have been up to 8–10 orders of magnitude higher than the data for volume diffusion coefficients and much greater than for diffusion at the stationary grain boundaries of Zn in pure Fe. This is clear indication that the rate controlling factor for DP reaction in the Fe-13 at.% Zn alloy is diffusion at the moving RF.

6

Wpływ innowacyjnego medium piaskującego na połączenie tytan – porcelana dentystyczna

Lubas Małgorzata

Materiały Ceramiczne

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2019

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T. 71, nr 3

276--285

PL

W pracy przedstawiono wyniki badań stanu powierzchni próbek tytanowych (Grade 2) po przeprowadzanej obróbce mechanicznej z zastosowaniem różnych mediów piaskujących. Topografię powierzchni próbek metalicznych po procesie piaskowania zobrazowano za pomocą mikroskopu sił atomowych AFM. Przeprowadzone badania pozwoliły określić podstawowe parametry chropowatości - Ra, Rq i Rmax. Do piaskowania wykorzystano mieszaninę Al2O3/NaAlSi3O8/ZrO2-TiO2 oraz tradycyjnie stosowany w pracowniach protetycznych piasek korundowy (100% Al2O3). Na podstawie badań wytrzymałościowych (metoda trzypunktowego zginania) oraz badań mikroskopowych (SEM/EDS) określono wpływ zastosowanego medium piaskującego na jakość połączenia metal-porcelana dentystyczna.

EN

The paper presents the results of tests on the surface condition of titanium samples (Grade2) after mechanical machining with the use of various sandblasting media. The topography of the surface of metallic samples was depicted after the sand blasting process by an atomic force microscope AFM. The tests allowed to determine the basic parameters of roughness - Ra, Rq and Rmax. A mixture of Al2O3/NaAlSi3O8/ZrO2-TiO2 and corundum sand (100% Al2O3) traditionally used in prosthetic laboratories was used for sandblasting. On the basis of strength tests (three-point bending method) and microscopic tests (SEM/EDS), the influence of the sandblasting medium used on the quality of the metal-dental porcelain joint was determined.

7

Hybrid ZnO/ZnO-NPs nanofibres fabricated via electrospinning

Matysiak W., Zaborowska M.

Journal of Achievements in Materials and Manufacturing Engineering

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2019

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Vol. 94, nr 1-2

5--12

EN

Purpose: Due to the growing interest and multitude of possible applications, zinc oxide nanowires, including those doped with ZnO nanoparticles, can became, alongside carbon nanotubes, a very desirable material which use is predicted in the construction of nanogenerators, dye sensitized solar cells, optoelectronics or ultrasensitive gas detectors. Design/methodology/approach: The electrospinning process allows for low-cost and scalable production of fibrous mats with diameters from a few to several hundred nanometers. What is more, electrospinning method has gained popularity also due to its versatility, now it is possible to produce fibres from almost every known polymer and the simplicity and lack of any additional functionalization of the obtained nanomaterials. The application of the calcination process to remove the polymer matrix from the obtained nanofibres results in the creation of ceramic nanofibres. Findings: Among the existing methods for the production of ceramic nanostructures, including the hydrothermal, physical and chemical vapour deposition methods, nanolithography or molecular self-assembly, the electrospinning process creates the possibility of fabricating one-dimensional nanostructures with unprecedented properties, good quality, no additional functionalization and purification. Research limitations/implications: Due to ongoing research on the potential applications of zinc oxide nanostructures, including photovoltaics, sensorics and electronics, the most predictable behaviour and properties of ZnO nanowires characterize those nanomaterials that exhibit a periodic structure of the crystal lattice. Considering the optimization of the parameters of the method of producing ceramic zinc oxide nanowires doped with crystalline ZnO nanoparticles, it is worth analysing the thermal treatment parameters of nanofibres. Practical implications: Although amorphous structure, hybrid ZnO nanofibres could be used as humidity sensors with much higher sensing properties than crystalline ZnO nanostructures. Originality/value: Low-cost, scalable production of ceramic nanofibres for most technical applications.

8

Morphology and composition of particulate matter in the air of urban area

Loskot Jan, Kumar D. Kishore, Komárek Jan, Sajdlová Světlana, Křiž Jan, Ziembik Zbigniew

Ecological Chemistry and Engineering. A

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2019

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Vol. 26, nr 1-2

59--71

EN

Atmospheric pollution by particulate matter has become increasingly important in recent years, because it was found that these airborne particles have various adverse effects on the environment and human health. To extend the knowledge of such pollutants, detailed characterization of sizes, morphology and chemical composition of individual airborne particles is desired. In the presented research, the air microparticles were taken from discarded fiberglass tape filters which are commonly used in MP101M continuous suspended particulate analysers to determine the mass concentration of the particulate matter. These samples, which were collected in Kutna Hora (Czech Republic), were studied using the methods of scanning electron microscopy and energy-dispersive X-ray spectroscopy. Based on microscopic photographs, various geometrical parameters (Feret’s diameter, perimeter, cross-section surface area, circularity, aspect ratio, roundness and solidity) of 237 particles were assessed, while the spectroscopy measurements revealed elemental composition of these particles. Statistical evaluation of the measured data was done using the methods of principal component analysis and compositional data analysis. By these methods, certain relationships among the geometrical parameters and the content of chemical elements in the particles were found. This research also demonstrated that the fiberglass air filters can easily be reused to gain additional information about airborne particles in various places at any time. The character of the particles can also provide information about a possible source of contamination.

PL

Zanieczyszczenie powietrza przez pył zawieszony (PM) staje się w ostatnich latach coraz bardziej znaczące. Stwierdzono, że unoszące się w powietrzu cząsteczki niosą różne niekorzystne skutki dla środowiska i zdrowia ludzkiego. Aby poszerzyć wiedzę na temat takich zanieczyszczeń, pożądana jest szczegółowa charakterystyka rozmiarów, morfologii i składu chemicznego poszczególnych cząstek zawieszonych w powietrzu. W prezentowanych badaniach mikrocząsteczki powietrza zostały pobrane z filtrów taśmowych z włókna szklanego, które są powszechnie stosowane w analizatorach cząstek stałych MP101M. Próbki zostały zebrane w Kutnej Horze (Republika Czeska), były badane metodami skaningowej mikroskopii elektronowej i spektroskopii rentgenowskiej z rozpraszaniem energii. Na podstawie zdjęć mikroskopowych oceniono różne parametry geometryczne (m.in. średnicę Fereta, obwód, powierzchnię przekroju poprzecznego, krągłość, współczynnik kształtu) 237 cząstek, a pomiary spektroskopowe pozwoliły na określenie składu pierwiastkowego tych cząstek. Statystyczną ocenę otrzymanych wyników wykonano metodami analizy głównych składowych i metodami analizy zmiennych złożonych. Stwierdzono istnienie pewnych zależności pomiędzy parametrami geometrycznymi a zawartością pierwiastków chemicznych w cząstkach. Badania te wykazały również, że filtry powietrza z włókna szklanego mogą być z łatwością ponownie wykorzystane do uzyskania dodatkowych informacji o cząstkach zawieszonych w powietrzu w różnych miejscach w dowolnym czasie. Charakter cząsteczek może również dostarczyć informacji o możliwym źródle zanieczyszczeń.

9

Ślady krwi na Całunie Turyńskim : analiza materiałowa od mikro do nanoskali

Jaworski J. S.

Wiadomości Chemiczne

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2018

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[Z] 72, 1-2

61--80

EN

Modern experimental methods of materials science including optical and electron microscopy (SEM, ESEM, HRTEM), X-ray spectroscopy (EDX, WAXS), Raman and FTIR spectroscopy used in investigations of structures of new materials can be also successfully applied for analysis of archeological, cultural heritage and art objects. An interesting example of such analyses are investigations of microscopic fibers and particles taken previously from areas attributed to the blood on the Shroud of Turin. Detailed analyses performed by a number of research groups published in 2015–2017 are reviewed. They confirmed previous hypothesis on blood authenticity and discovered new evidences indicated a violence hidden behind the death. In particular, the presence of old red blood cells was documented by Lucotte [20], of bile pigment biliverdin by Laude and Fanti [28], of iron oxide cores of ferritin bounded to nanoparticles of creatinine by Carlino et al. [31]. The last result is typical for patients with severe polytrauma indicating at the unexpected nonoscopic level a tremendous suffering of the victim wrapped in the Shroud of Turin. Bigger particles of mineral pigments: ochre (iron oxide) and vermillion (mercury sulfide) were also found but they can be easily distinguished form blood particles using environmental electron microscopy ESEM with the back-scattered electrons detector [24]. The statistical analysis of a sample composition made by Fanti and Zagotto [24] indicated that 90–95% of the observed volume corresponds to the blood and only remainder represents inorganic pigments. Thus, it was proposed [24] that the original human blood on Shroud stains was much later reinforced by red pigments using a color dust without any binder and this hypothesis can easily explain controversies between previous results of different researches.

10

Mikrostruktura i właściwości mechaniczne wielowarstwowych platerów na bazie Al i Ti wytwarzanych z wykorzystaniem energii wybuchu

Paul H., Prażmowski M., Gałka A., Miszczyk M.

Przegląd Spawalnictwa

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2018

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R. 90, nr 4

63--65

PL

W pracy analizowano zmiany mikrostrukturalne oraz formowanie się nowych faz w wielowarstwowych układach platerów zbudowanych na bazie Ti i Al. Wykorzystano techniki mikroskopii optycznej i skaningowej mikroskopii elektronowej, pomiary mikrotwardości, a także próbę zginania w warunkach udarowych. Obserwacje w skali makro pokazały, że w procesie spajania wytworzono 15-warstwowy plater wolny od nieciągłości strukturalnych. Powierzchnie połączenia uległy silnemu odkształceniu i wykazywały mieszany falisto-płaski charakter ze strefami przetopień preferencyjnie lokowanymi na grzbiecie oraz w zawinięciach fal. Zaobserwowano, że silnie pofalowane granice połączenia zawsze formowały się w warstwach położonych w pobliżu ładunku wybuchowego. Analizy w mikro skali udokumentowały występowanie cienkiej warstwy przetopionej o silnie rozdrobnionej strukturze.

EN

Microstructure and phase in the bonding zone of explosively welded Ti/Al multilayer clads were examined by optical microscopy and scanning electron microscopy. The defect-free multilayer composite was successfully formed. The macro-scale observations showed that the interfaces between joined plates presented mixed wavy/flat shape with solidified melt inclusions located preferentially at the crest of each wave and in the wave vortex. It was found that interfaces of wavy character were always formed in layers near the explosive charge and flattened with the increase of the distance from the top surface. The micro-scale analyses observations revealed a presence of very thin reaction layer at the flat parts of the joint plates and nano-grained structure of melted zones.

11

Characterization of magnesium LAE442 alloy microstructure after deformation process with the use of KoBo method

Bednarczyk I.

Inżynieria Materiałowa

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2018

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Vol. 39, nr 2

56--60

EN

At present, there is a growing demand of the aviation industry on the parts prepared from light alloys which are characterised with sufficient stiffness and resistance. The technology of plastic deformation of magnesium alloys is a huge challenge. Due to the low plasticity of those materials in room temperature the parameters of the process of plastic working must be a satisfying compromise between the cost and the quality of the products. Due to those facts, alternative methods of plastic deformation of magnesium alloys need to be found. Particularly promising results in terms of the improvement in the susceptibility to plastic deformation are brought by new ultra-light magnesium alloys containing lithium. With the introduction of lithium, the density of which is 0.535 g/cm3, into the chemical composition of alloy, a further decrease of weight of alloy is achieved but at the same time the resistance of the material decreases. The article presents the results of tests of plastic deformation of Mg–Li–RE magnesium alloys. Alloys for extrusion process were achieved with the method of vacuum melting and casting to graphite moulds. The materials for tests were cast slabs from magnesium alloys with symbols LAE442. Before the process of deformation the castings were subject to homogenization. The tests of extrusion were conducted in complex state of deformation with using KOBO method. An assessment was performed of the influence of deformation process parameters on the microstructure of tested alloy. An analysis of microstructure was conducted both in initial condition and condition after plastic deformation with the use of techniques of light and scanning transmission electron microscopy.

PL

Obecnie obserwuje się rosnące zapotrzebowanie przemysłu lotniczego na części wykonane ze stopów magnezu, które spełnią określone wymagania wytrzymałościowe. Jednak mała plastyczność stopów magnezu w temperaturze pokojowej powoduje, że są poszukiwane alternatywne sposoby kształtowania tej grupy materiałów. Szczególnie obiecujące w zakresie poprawy podatności do kształtowania plastycznego są nowe ultralekkie stopy magnezu zawierające w swoim składzie chemicznym lit. W artykule przedstawiono wyniki analizy mikrostruktury prętów otrzymanych ze stopu LAE442 po procesie odkształcenia metodą KoBo. Określono zmiany powstałe w mikrostrukturze stopu LAE442 po odkształceniu plastycznym metodą KoBo.

12

Synthesis, microstructure and mechanical properties of bronze–molybdenum composites processed via LPS and SPS methods

Memari S., Ardestani M., Abbasi A.

Archives of Civil and Mechanical Engineering

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2018

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Vol. 18, no. 4

1013--1023

EN

In this work, synthesis, densification and properties of bronze–70 wt% Mo and bronze–30 wt% Mo composite powders were investigated. The composite powders were prepared by mechanical milling of bronze–Mo powder mixtures for 16 h. The results of cold compressibility investigations showed that Heckel and Ge equations provided the best fit scenario for bronze–70 wt% Mo and bronze–30 wt% Mo, respectively. The composite powders were consolidated via pressureless and spark plasma sintering processes. The relative densities of spark plasma sintered samples with 30 and 70 wt% molybdenum were about 98%. However, the relative density of bronze–70 wt% Mo and bronze–30 wt% Mo pressureless sintered samples were 97.1 and 94.3%, respectively. The scanning electron microscopy observations revealed that the size and dispersion of Mo particles within the bronze matrix in the pressureless sintered samples was completely different from that of the spark plasma sintered ones. Furthermore, it was found that in spite of nearly close relative densities, the hardness and flexural strength of the spark plasma sintered samples were higher than that of the pressureless sintered ones which was due to different shape, size and dispersion of the Mo particles within the matrix phase in the different samples. According to the results, the preferred densification process was SPS method.

13

Mechanical strength of epoxy/organoclay/carbon fiber hybrid composites

Oliwa R., Heneczkowski M., Oliwa J., Oleksy M.

Polimery

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2017

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T. 62, nr 9

658--665

EN

The influence of organoclay (bentonite BS) modified with quaternary ammonium (QAS) and phosphonium salts (QPS) on the mechanical properties of epoxy/organoclay/carbon fiber hybrid composites was investigated. The longitudinal flexural strength of the composites containing 1 wt % BSQAS and BSQPS increased by 4 and 10 %, respectively, compared to the reference sample (epoxy resin/carbon fiber). Moreover, there was also a significant improvement, up to 13 %, of Young's modulus and transverse elastic modulus for the composites with modified bentonites. On the basis of the atomic force microscopy cross-section analysis (AFM), it was found that the composites with matrix containing the modified bentonites were characterized with larger interfacial surface, about 50 %, than that of unmodified matrix (epoxy resin/carbon fiber).

PL

Zbadano wpływ dodatku glinokrzemianu (bentonit BS) modyfikowanego czwartorzędowymi solami amoniowymi (QAS) lub fosfoniowymi (QPS) do nienasyconej żywicy epoksydowej (EP6) na właściwości mechaniczne hybrydowych kompozytów wzmocnionych włóknem węglowym (żywica epoksydowa/glinka/włókno węglowe). Stwierdzono, że dodatek 1 % mas. BSQAS lub BSQPS do osnowy żywicy EP6 powoduje zwiększenie wytrzymałości na zginanie w kierunku równoległym do ułożenia włókien węglowych o, odpowiednio, 4 i 10 % w porównaniu z wytrzymałością kompozytów na osnowie niemodyfikowanej (żywica epoksydowa/włókno węglowe). Dzięki modyfikacji uzyskano również wyraźną poprawę (powyżej 13 %) modułu Younga oraz modułu elastyczności. Na podstawie badań z zastosowaniem mikroskopii sił atomowych (AFM) stwierdzono, że kompozyty na osnowie żywicy epoksydowej zawierającej modyfikowane glinokrzemiany charakteryzują się większą (o ok. 50 %) powierzchnią międzyfazową na granicy włókno węglowe-polimer niż kompozyty na osnowie żywicy bez udziału glinki (żywica epoksydowa/włókno węglowe).

14

Microscopic and spectroscopic investigation of carbon nanotubes-rhenium nanocomposites fabricated in different conditions

Dobrzańska-Danikiewicz A. D., Wolany W., Gołombek K.

Archives of Civil and Mechanical Engineering

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2017

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Vol. 17, no. 4

978--985

EN

The article describes the morphology of carbon-metal nanocomposites consisting of nanostructured rhenium permanently attached to carbon nanomaterials, in the form of single-walled (SWCNTs), double-walled (DWCNTs) or multi-walled carbon nanotubes (MWCNTs). Such nanocomposites are produced as a result of the high-temperature reduction of a rhenium precursor, including HReO4 or NH4ReO4, to metallic rhenium, deposited on the previously functionalised carbon nanomaterials in the form of nanoparticles whose size and dispersion are dependent upon the conditions of a technological process. Microscopic examinations carried out with scanning electron microscopy (SEM) and transmission electron microscopy (TEM) confirmed a differentiated structure of the presented nanocomposites depending on impregnation time in a rhenium precursor, which is one of the manufacturing steps of such materials. It has been demonstrated that longer impregnation time brings favourable results for material homogeneity in the whole volume. Moreover, the Raman spectroscopy results of functionalised carbon nanotubes and carbon nanotubes decorated with rhenium also has been presented.

15

Copper/nanodiamond composite coatings obtained by electrochemical deposition

Buczko Z., Gniadek M., Olkowicz K., Okurowski W.

Inżynieria Materiałowa

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2016

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Vol. 37, nr 6

306--310

EN

Copper composite coatings with nanodiamond particles were electrochemically deposited. Depositions were made on copper sheet basis in acid sulphate solutions with and without organic additives. The studies indicate the possibility of electrochemical deposition of composite Cu/diamond coatings and the coating properties depend on solutions composition. The concentration of the diamond preparation in process electrolyte solutions was about 0.5 g/dm3. The composites surface morphology was investigated by SEM microscopy and chemical composition with EDS microanalysis. Concentrations of diamond particles in samples surfaces were evaluated by ImageJ computer analysis. Hardness of coatings were measured by Vicker’s method.

PL

Kompozyty o osnowie metalicznej z fazą dyspersyjną są obecnie intensywnie badane w celu opracowania metod wytwarzania materiałów o ulepszonych właściwościach mechanicznych, tribologicznych, elektrycznych, cieplnych i innych. Istotnym obszarem zastosowań są urządzenia elektroniczne. Postępująca miniaturyzacja urządzeń powoduje problemy związane z odprowadzaniem ciepła z układów scalonych. Miedź jako osnowa jest materiałem atrakcyjnym ze względu na dobre przewodnictwo elektryczne, ale również dobre parametry mechaniczne, takie jak np. plastyczność. Podejmowane są próby wprowadzania jako fazy dodatkowej cząstek węglowych, na przykład takich jak diament. Materiał ten charakteryzuje się dużym przewodnictwem cieplnym oraz małym współczynnikiem rozszerzalności cieplnej. Diament jest również najtwardszym znanym materiałem. Jako faza dyspersyjna może korzystnie wpływać na właściwości kompozytu. Próby uzyskania materiału kompozytowego miedzi z diamentem są podejmowane różnymi metodami, m.in. w procesie spiekania, ale również poprzez elektrolityczne osadzanie. Celem pracy było zbadanie możliwości elektrolitycznego osadzania materiałów kompozytowych na osnowie miedzi, zawierających cząstki nanodiamentu oraz ocena ich podstawowych właściwości takich jak skład chemiczny, twardość oraz morfologia powierzchni powłoki.

16

Ultrasonic-assisted synthesis of reactive carboxymethyl cellulose stabilized nano zero-valent iron and its application for removal of Cr6+ and Cu2+ ions

Ayob A., Santiagoo R., Amneera W. A., Ismail N., Abdullah A. Z.

Environment Protection Engineering

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2016

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Vol. 42, nr 2

55--79

EN

Carboxymethyl cellulose (CMC) was used in the chemical reduction using sodium borohydride to yield dispersive nano zero-valent iron (nZVI) particles as reactive and stable adsorbents. CMC- -stabilized nZVI particles were characterized via UV-visible light spectroscopy, X-ray diffraction, dynamic light scattering, transmission electron microscopy, and specific surface area assisted using a probe ultrasonication dispersing tool at 50% amplitude power. High catalytic reactivity obtained in pseudo-first order reaction for Cr6+ (rate constant K1 = 0.0311 min–1) and pseudo-second order for Cu2+ (rate constant K2 = 0.0946 g·mg–1·min–1) indicated that colloidal stability of nZVI particles can be achieved with a stabilizer for the removal of toxic contaminants.

17

Adsorptive performance of MCM-41 towards hg(II) in water. Adsorption and desorption studies

Zhai Q. Z., Hu W.-H., Guo X.-Y.

Environment Protection Engineering

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2016

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Vol. 42, nr 1

5--15

EN

MCM-41 mesoporous material was prepared under a standard conditions by using cetyltrime-thylammonium bromide as a structure-directing agent and tetraethyl orthosilicate as silica source from the liquid phase at 80 °C. Powder X-ray diffraction and scanning electron microscopy used to characterize the product, showed that the MCM-41material had an average particle size of 110 nm. The synthesized material was used to investigate the effects of acidity, adsorption time, the concentration of Hg2+, adsorbent dosage and temperature on the adsorption of Hg2+. The results showed that the optimal adsorptive conditions were: pH 5.0, m(MCM-41):mHg2+ 6.67, temperature 20 °C and contact adsorption time 60 min, for the initial Hg2+concentration of 1.0 mg/cm3. The maximum adsorptive amount of Hg2+ was 56.48 mg Hg2+/g MCM-41. The results of the desorptive effect of three desorption agents such as HCl, HNO3 and HAc showed that the best desorbent was HCl at the concentration of 0.10 mol/dm3. The highest desorption efficiency was 77.21% for the desorption time 2 h.

18

Silver matrix composites consolidated and hot extruded from ball milled powders strengthened with different types of graphene platelets

Dutkiewicz J., Ozga P., Pstruś J., Maziarz W., Grzegorek J.

Composites Theory and Practice

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2016

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R. 16, nr 4

207--211

EN

Silver matrix composites containing 1÷2% graphene platelets of various thicknesses were uniaxially hot pressed at 480°C in vacuum from powders ball milled for 5 hours. Two kinds of graphene nanoplatelets were added: (i) - nanoflakes (FLRGO) of a thickness 2÷4 nm, which led to a higher hardness (35÷49 HV) and slightly lower electrical resistivity of the composites, than that of pure hot pressed Ag and (ii) - nanographite platelets (N006) 10÷20 nm thick as confirmed by electron microscopy, which caused a similar increase in hardness up to 34÷45 HV and about a 40% higher electrical resistivity than that of pure hot pressed Ag. SEM studies showed a more homogeneous microstructure of the composites with the FLRGO graphene additions. TEM studies confirmed refinement of the thickness and lateral size of the graphene particles after milling and hot compaction down to a few nm manifested by diffused electron diffraction. The hot extrusion of hot pressed composites with FLRGO platelets caused the growth of graphene platelets and coagulation of the platelets, which contributed to a higher hardness and electrical resistivity.

PL

Kompozyty na osnowie srebra z dodatkiem płytek grafenowych o różnej grubości zostały wykonane poprzez jednoosiowe prasowanie w temperaturze 480°C z proszków mielonych 5 godzin w młynkach kulowych. Zastosowano dwa rodzaje płytek grafenowych: (i) nanopłatki FLRGO z firmy Nanomaterials o grubości 2÷4 nm, które powodowały wzrost twardości kompozytów na osnowie srebra, do wielkości 35÷49 HV i nieznaczny spadek oporności w stosunku do czystego prasowanego z proszku srebra oraz (ii) płytki nanografitu N006, których dodatek w ilości 2% wag. potwierdzono za pomocą dyfrakcji rentgenowskiej i elektronowej z firmy Angstron Materials o grubości płytek 10÷20 nm, powodował wzrost twardości do 34÷45 HV i oporności elektrycznej o około 40% w stosunku do czystego prasowanego z proszku srebra. Badania mikrostruktury metodami SEM wykazały występowanie bardziej jednorodnej mikrostruktury w kompozytach zawierających płytki grafenowe FLRGO. Badania TEM wykazały rozdrobnienie płytek N006 po mieleniu i prasowaniu, co powodowało silne rozmycie refleksów 002 grafenu w związku ze zmniejszeniem wielkości cząstek w płytkach do kilku nm. Prasowanie na gorąco spowodowało z kolei wzrost wielkości cząstek w płytkach i koagulację płytek, co wpłynęło na wzrost twardości i oporności elektrycznej.

19

Modification of zirconium alloy surface using high intensity pulsed plasma beams

Sartowska B., Starosta W., Barlak M., Walis L.

Archives of Materials Science and Engineering

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2016

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Vol. 77, nr 2

53--57

EN

Purpose: The aim of the research was to identify possibility of extending the life time of zirconium claddings. Materials used in nuclear reactors work in extremely hard conditions: irradiation, corrosion, stress. Zirconium alloys, due to their good water corrosion and radiation resistance at normal working conditions of nuclear reactors are used as cladding material for fuel elements. In the case of loss-of-coolant accident (LOCA), the extremely fast oxidation of zirconium at steam or air/steam mixture at temperatures above 800°C results in intense hydrogen generation and possible hydrogen-oxide mixture explosion. The development of the solution to minimize the risk of the accidents mentioned above is urgently needed. The concept of Accident Tolerant Materials (ATM) has been developed recently. Design/methodology/approach: Zirconium surface were treated with 30 high intensity pulsed plasma beams (HIPPB) Cr+Ar, Y+Ar or Al+Ar, with energy density of 4.0 J/cm2. Oxidation tests: autoclave (water, 360°C, 19.50 MPa) for 7 and 40 days and oven (700°C and 800°C/1000 s/air) followed by cooling in water were performed. Samples were characterised with: SEMs, EDS and GXRD. Findings: Zirconium samples with modified surface layer showed the higher resistance for oxidation in simulated conditions of normal work of PWR reactor and in elevated temperatures. Originality/value: Carried out work was connected with new concept of development accident tolerant materials - ATM.

20

Efficiency of the compression with oscillatory torsion method in grain refinement in Al

Rodak K., Pawlicki J.

Archives of Civil and Mechanical Engineering

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2016

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Vol. 16, no. 4

805--812

EN

Experiments were conducted to investigate the development of an ultrafine grain structure during compression with oscillatory torsion processing of high-purity aluminum (99.9%) with an initial grain size of 75 μm. The samples were processed using different deformation parameters: torsion frequency (f) and compression rate (v). The samples were examined using a scanning electron microscope equipped with a field emission gun and an electron backscattered diffraction detector. The results suggest that for high-purity aluminum an ultrafine-grained microstructure was obtained after a total effective strain (ɛft) of 45 in samples deformed at f = 1.6 Hz and v = 0.04 mm/s. A quantitative study of the microstructural parameters showed that the area fraction of the ultrafine grains (<1 μm) (A1μm) was 44%, the fraction of high-angle boundaries was 53%, and the average diameter of the grains was about 600 nm. The yield stress and ultimate tensile stress reached 127 and 137 MPa, respectively, after deformation at a total effective strain of 45. When the total effective strain reached 120, the mechanical strength of the material decreased. This suggests that the decrease in strength is associated with the operation of the recovery mechanism that decreases the boundary volume.