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1

Shape accuracy in single point incremental forming of conical frustums from titanium CP2 sheets

Szpunar Marcin, Balcerzak Maciej, Żaba Krzysztof

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

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2022

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z. 94

63--75

EN

This paper presents frustum cone drawpiece analysis made of titanium CP2 sheet by a single incremental sheet forming. Central composite design has been adopted to carry out an experiment containing 20 runs, then multi-criteria parameter optimization has been done. Optimal parameters have been validated and responses deviations do not exceed 4% compared to created models. For the drawpiece formed with optimal parameters, AGRUS optical measurement and X-ray tomography has been applied to check the obtained of the part wall thickness and general deviations compared to the CAD model. The wall angle discrepancy of the cone generatrix has also been analyzed. No gaps or ruptures have been confirmed by X-ray. The blank rolling direction has a significant effect on the drawpiece deviations. The measurement results showed deviations of the drawpiece wall angle +0.27°/- 0.06°, sheet thickness on the cone +0.012/-0.04 mm and +0.151/-0.096 mm from the reference CAD geometry.

PL

W pracy przedstawiono analizę wytłoczek w kształcie stożka ściętego wykonanego z blachy tytanowej CP2 metodą jednopunktowego przyrostowego kształtowania. Do przeprowadzenia eksperymentu obejmującego 20 przebiegów przyjęto centralny plan kompozycyjny, następnie dokonano wielokryterialnej optymalizacji parametrów. Dokonano walidacji optymalnych parametrów, a uzyskane wyniki nie przekraczają 4% w odniesieniu do stworzonych modeli. Dla wytłoczki uformowanej z optymalnymi parametrami zastosowano pomiar optyczny AGRUS oraz tomografię rentgenowską w celu sprawdzenia uzyskanej grubości ścianki wytłoczki i odchyłek w porównaniu z modelem CAD. Przeanalizowano również rozbieżność kątów ścian tworzących stożka. Za pomocą skanu rentgenowskiego potwierdzono brak szczelin i pęknięć wytłoczki. Kierunek walcowania półfabrykatu ma istotny wpływ na odchyłki. Wyniki pomiarów wykazały odchylenia kąta ścianki wytłoczki +0,27/-0,06°, grubości ścianki na stożku +0.012/-0.04 mm oraz +0.151/-0.096 mm od geometrii referencyjnej CAD.

2

Badanie betonu geopolimerowego z kruszywem z żużla żelazochromowego na działanie podwyższonej temperatury

Indu P., Greeshma S.

Cement Wapno Beton

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2021

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R. 26, nr 4

340--351

PL

Niniejszy artykuł dotyczy wytrzymałości i ubytku masy betonu geopolimerowego w porównaniu z konwencjonalnym betonem cementowym, po ekspozycji w podwyższonej temperaturze. W niniejszej pracy kruszywo grube konwencjonalnego betonu geopolimerowego zostało częściowo (40%) zastąpione kruszywem z żużla żelazochromowego w celu uzyskania mieszanki zastępczej betonu geopolimerowego. Omówiono również mikrostrukturę betonu geopolimerowego na podstawie badań XRD, SEM i tomografi i rentgenowskiej. W wyniku badań stwierdzono, że po ekspozycji w podwyższonej temperaturze, konwencjonalny beton cementowy wykazuje spadek wytrzymałości większy o 17,65% od konwencjonalnego betonu geopolimerowego. Zauważono również, że zastępcza mieszanka geopolimerowa wykazuje utratę wytrzymałości o 24,4% większą i utratę masy o 1,35% większą niż konwencjonalna mieszanka geopolimerowa. Jednak w większości zakresów temperatur miała ona większą wytrzymałość od konwencjonalnej mieszanki geopolimerowej. Tak więc mieszanka zastępcza betonu geopolimerowego zachowuje się lepiej niż konwencjonalny beton geopolimerowy i konwencjonalny beton cementowy zarówno w warunkach otoczenia, jak i w podwyższonej temperaturze.

EN

This paper deals with the strength and mass loss of geopolymer concrete in comparison with conventional cement concrete after elevated temperature exposure. In this study, the coarse aggregates of the conventional geopolymer concrete are replaced partially (40%) with ferrochrome slag aggregates, to obtain the replacement mix of geopolymer concrete. The microstructure of geopolymer concrete was examined by XRD, X-ray tomography, and SEM and also discussed in this paper. The results concluded that after exposure at elevated temperature, the conventional cement concrete has a strength loss of about 18% higher than the geopolymer concrete. It was also noted that though replacement geopolymer mix exhibited the strength loss of 24.4% and mass loss of 1.35% higher than the conventional geopolymer mix, it had greater strength than conventional geopolymer mix, for most of the temperature ranges. Thus the replacement mix of geopolymer concrete behaves better than conventional geopolymer concrete, both at ambient and elevated temperature conditions.

3

Identification of changes in mechanical properties of sandstone subjected to high temperature: meso-and micro-scale testing and analysis

Różański Adrian, Różańska Anna, Sobótka Maciej, Pachnicz Michał, Bukowska Mirosława

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 1

461--482

EN

Material properties largely depend on their structure, and are strongly dependent on the scale of observation. Under the influence of various processes, the structure of a material can undergo evolution, which leads to major changes in the mechanical parameters and morphology of the medium. To understand the behaviour of a given material exposed to the influence of various factors, e.g. loading and temperature treatment, and to be able to modify it appropriately, it is crucial to recognize its structure both in the scale of engineering applications and at the micro-scale. The article proposes a procedure for assessing changes in the structure of sandstone exposed to the temperature treatment. The presented procedure allows the morphology of the material to be evaluated and the influence of temperature treatment on mechanical parameters of rocks to be analysed, by combining use of different laboratory techniques. The changes in rock material have been characterized using three investigative techniques, i.e. a uniaxial compression test, nanoindentation and micro-computed tomography. The uniaxial compression tests were carried out for 11 different temperature values in the range of 23–1000 °C, which enabled the determination of the change in uniaxial compressive strength and Young’s modulus of the sandstone as a function of temperature. Micro-scale laboratory tests were utilised to identify changes in the mechanical and morphological parameters of the sandstone exposed to the temperature of 1000 °C. The results were referred to those obtained for the reference samples, i.e. not subjected to heating (T = 23 °C). Comparison of the results showed an evident relation between the microstructure changes and the mesoscopic properties.

4

A study on fibre-reinforced concrete elements properties based on the case of habitat modules in the underwater sills

Kurpińska Marzena, Grzyl Beata, Kristowski Adam

Polish Maritime Research

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2020

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nr 1

143--151

EN

Hydrotechnical constructions are mostly objects functioning in extreme conditions and requiring a custom-made construction project. In the case of using prefabricated elements, it is required to develop production, transport, assembly, conservation and repair technology. Concerning the problem of concrete cracks, modern repair systems allow positive effects to be achieved in many cases of concrete elements repair. In this work an attempt has been made to assess the properties of concrete, situated in the Baltic Sea environment, in which traditional rebar was partly replaced by dispersed fibre-phase. Fibre-reinforced concrete belongs to the group of composite materials. The presence of fibres helps to increase the tensile strength, flexural strength and resilience and also prevents the appearance of cracks. In the given paper we will also discuss basic parameters of steel and polymer fibres and the influence of both types of fibres on the maturing and hardened concrete. In this work special attention has been paid to the advantages of polypropylene and polymer fibres with regard to commonly-known steel fibres. The use of synthetic fibres will be advantageous in constructions where the reduction of shrinkage cracks and high resilience are essential. On top of that, the use of synthetic fibres is highly recommended when constructing objects that will be exposed to the impact of an aggressive environment. Undoubtedly, polymer fibres are resistant to the majority of corrosive environments. Fibre-reinforced concretes are a frequently implemented construction solution. The possibility of concrete modification allows the emergence of new construction materials with improved physical-mechanical properties, under the condition of being applied relevantly.

5

Study of Nonmetallic Inclusions in Aluminum–Silicon Alloys

Galek Tomasz, Łączek Andrzej, Łysiak Karol

Advances in Manufacturing Science and Technology

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2020

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Vol. 44, nr 1

28-31

EN

In this article, a study of nonmetallic inclusions introduced during the casting process of the aluminum–silicon alloy is presented. The samples were investigated using a scanning electron microscope to find the chemical composition and X-ray tomography to check the volumetric content of the non-metallic inclusions. The samples were made from AlSi7Mg alloy, used for car wheels, with 7% weight content of Si, 89% of Al, and 0.3% of Mg. The main goal of our investigations was to find out the chemical composition of the impurities and to identify the stage of the casting process at which the impurities are introduced.

6

X-ray computer tomography study of degradation of the zirvaloy-2 tubes oxidized at high temperatures

Trybuś B., Olive J. M., Lenoir N., Zieliński A.

Advances in Materials Science

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2019

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Vol. 19, nr 2(60)

54--71

EN

The investigations of high-temperature oxidation of zirconium alloys, applied for fuel pellets in nuclear power plants, are usually limited to oxidation kinetics, phase transformations and microstructural characterization. The purpose of this research was to characterize the degradation phenomena occurring within oxide layer and at the interface oxide/metal, on internal and external Zircaloy-2 tube surfaces, below and over crystalline transformation temperature of zirconium oxides. The commercial tubes were oxidized at 1273 K and 1373 K in calm air for 30 min and then examined with a technique novel for such purpose, namely a high-resolution X-ray computer tomography. The light microscopy was used to examine the cross-surfaces. The obtained results show that the form and intensity of oxide damage is significant and it is in a complicated way related to oxidation temperature and on whether external or internal tube surface is studied. The found oxide layer damage forms include surface cracks, the detachment of oxide layers, the appearance of voids, and nodular corrosion. The oxidation effects and damage appearance are discussed taking into account the processes such as formation of oxides, their phase transformation, stress-enhanced formation and propagation of cracks, diffusion of vacancies, formation of nitrides, diffusion of hydrogen into interface oxide-metal, incubation of cracks on second phase precipitates are taken into account to explain the observed phenomena.

7

Charakterystyka mikrostruktury pianobetonu o różnych gęstościach przy zastosowaniu technik mikroskopowych

Chung S. Y., Lehmann C., Elrahman M. A., Stephan D.

Cement Wapno Beton

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2018

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R. 21/83, nr 3

216--225

PL

W pracy przedstawiono wyniki badań próbek pianobetonów z użyciem skaningowej mikroskopii elektronowej oraz mikrotomografii rentgenowskiej. Scharakteryzowano porowatość oraz właściwości matrycy cementowej betonów po różnych czasach dojrzewania. Gęstość decyduje w pierwszej kolejności o mikrostrukturze matrycy cementowej, a co za tym idzie właściwości pianobetonów. Jak można się było spodziewać, matryca cementowa jest bardziej zwarta w pianobetonach o większej gęstości i dojrzewających przez dłuższy okres. Średnica porów zmniejsza się, wraz ze zwiększaniem się gęstości betonów i jest bardziej stabilna w późniejszych okresach.

EN

In this paper a set of foamed concrete specimens with different densities was prepared, and microscopic techniques such as scanning electron microscopy and X-ray micro-computed tomography were used to characterize the specimens. The pore and solid characteristics of the foamed concrete at different ages were also examined to investigate the effect of aging on the materials. The microstructure of cement matrix and thus the properties of foamed concrete are strongly affected by the density of concrete. As it should be expected, the cement matrix is denser in concrete of higher density and concrete cured for longer period. The pore size distribution of the foamed concrete shows the tendency to be composed of smaller pores as the density of the specimens is increasing and to became more stable after longer curing period.

8

Identyfikacja wad powłok napawanych regeneracyjnie z zastosowaniem tomografii rentgenowskiej

Paszeczko M., Józwik J., Dziedzic K., Bereżanśkyj T.

Przegląd Spawalnictwa

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2017

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R. 89, nr 12

12--16

9

K-means clustering in textured image: example of lamellar microstructure in titanium alloys

Al Darwich R., Babout L., Strzecha K.

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2017

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T. 7, nr 3

43--46

EN

This paper presents an implementation of the k-means clustering method, to segment cross sections of X-ray micro tomographic images of lamellar Titanium alloys. It proposes an approach for estimating the optimal number of clusters by analyzing the histogram of the local orientation map of the image and the choice of the cluster centroids used to initialize k-means. This is compared with the classical method considering random coordinates of the clusters.

PL

W artykule przedstawiono implementację metody klasteryzacji k-średnich, do segmentacji dwuwymiarowych rentgenowskich obrazów mikro tomograficznych lamelarnych stopów tytanu. Zaproponowano metody szacowania optymalnej liczbę klastrów oraz wyboru centro idów poprzez analizę histogramu mapy lokalnych kierunków obrazu. Dokonano porównania zaproponowanych metod z losowym doborem początkowego położenia klastrów.

10

Study on the State of Internal Stress and Strain of TATB-based Polymer Bonded Explosive Using Strain Markers and Cone-Beam Computed Tomography

Dai B., Lan L.-G., Zhang W.-B., Tian Y.

Central European Journal of Energetic Materials

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2017

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Vol. 14, no. 3

688--707

EN

Precise measurement of the inner structural strain of polymer bonded explosive (PBXs) granules during compression molding is highly desirable in order to investigate the inner stress distribution field and its underlying generation mechanism, with the aim of improving the stress distribution uniformity. In this contribution, TATB-based (1,3,5-triamino-2,4,6-trinitrobenzene) PBX granules were formulated and the stress-strain state of the PBX granules during the warm molding process was analyzed. Strain markers were implanted at different locations and the deformation characteristics and regularity of the embedded spherical strain markers were obtained by X-ray micro-tomography. Thus the local strain states at different locations could be obtained, and the local stress state could be deduced. The results showed that axisymmetric deformation occurred in all of the strain markers, where the flat strain ellipsoids were mainly compressed uni-axially. In the central region, the stress was mainly in an axial direction, and the shear force was small. Not only axial stresses, but also large shear stresses in the surrounding region of the cylindrical grains were present. The stress gradient in the central region was greater than that in the surrounding region. The stress was greater in the surrounding region because this region was squeezed by the mold. The maximum strain degree was 44.8% larger than the minimum strain degree. The local stress increment in each region was quantified. The stress increments of the three axes were in the range 14.2-19.5 MPa. This study examined the feasibility of evaluating the inner stress–strain state of PBX granules in a quantitative manner, which is significant in determining the inner strain and stress distribution in PBX granules during the molding process.

11

Statistical Assessment of the Microstructure of Barite Aggregate from Different Deposits Using X-Ray Microtomography and Optical Microscopy

Żołek N., Ranachowski Z., Ranachowski P., Jóźwiak-Niedźwiedzka D., Kudela S. jr., Dvorak T.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 2A

697--702

EN

Two different barite ore (barium sulfate BaSO4) specimens from different localizations were tested and described in this paper. Analysis of the microstructure was performed on polished sections, and on thin sections using X-ray microtomography (micro-CT), and optical microscopy (MO). Microtomography allowed obtaining three-dimensional images of the barite aggregate specimens. In the tomograms, the spatial distribution of the other polluting phases, empty space as well as cracks, pores, and voids – that exceeded ten micrometers of diameter-were possible to visualize. Also, the micro-CT allowed distinguishing between minerals of different density, like SiO2 and BaSO4. Images obtained and analyzed on thin sections with various methods using the optical microscopy in transmitted light delivered additional information on the aggregate microstructure, i.e. allow for estimation of the different kinds of inclusions (like the different density of the minerals) in the investigated specimens. Above methods, which were used in the tests, completed each another in order to supply a set of information on inclusions’ distribution and to present the important differences of the barite aggregate specimens microstructure.

12

Metody badania porowatości odlewanych ciśnieniowo wyrobów ze stopu magnezu AM50

Sozańska L., Mazurkiewicz J.

Technical Issues

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2016

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nr 4

89--95

EN

There is an increasing interest in casting pressure elements in the automotive and household industry. Mechanical properties, implementation precision and quality play major role here. Unfortunately, this manufacturing technology is accompanied with disadvantageous features of the material structure as porosity, which must be controlled during production. On the basis of comparative studies of three selected research methods the most optimal research method for this group of products and materials was selected. It is a technique based on acoustic microscopy which, allows for the research of large components in the X and Y axes and a relatively high Z-axis. The research enables an analysis of all components without necessity of cutting a product into smaller elements subjected to separate analysis.

13

Izucenie netradicionnyh istocnikov uglevodorodov s ispol’zovaniem rentgenovskoj tomografii

Abrosimov A. A., Strel'cenko V. V.

Prace Naukowe Instytutu Nafty i Gazu

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2016

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nr 209 wyd. konferencyjne

751--755

RU

В нефтегазовой отрасли одной из актуальных задач является разработка месторождений нетрадиционных нефти и газа. Нефтегазовым компаниям необходимо получить рентабельную добычу углеводородов путем применения методов интенсификации флюидоизвлечения из продуктивных пластов, которые без знания структуры фильтрационно-емкостного пространства и учета фильтрационно-емкостных свойств, имеют, как правило, низкую эффективность. Однако в случае нетрадиционных источников, к которым можно отнести нефтематеринские глинистые породы и уголь, чаще всего невозможно проводить лабораторные эксперименты из-за их разрушенного состояния. В связи с этим, встает необходимость применения новых технологий, позволяющих изучать структуру фильтрационно-емкостного пространства и проводить оценку емкостных свойств подобных пород. Одним их таких методов на данный момент является рентгеновская томография. Использование данного метода позволяет визуализировать фильтрационно-емкостное пространство исследуемого образца, оценить значение его пористости. В работе демонстрируются возможности рентгеновской томографии на примере нетрадиционных источников углеводородов (нефтематеринских пород хадумской свиты и угля) и даются рекомендации по применению полученной информации.

EN

In the oil and gas industry one of the most urgent tasks is the development of deposits of unconventional oil and gas. Oil and gas companies need to get the cost-effective production of hydrocarbons by applying methods for oil and gas intensification of productive formations, which without the knowledge of the structure of pore space and consideration of reservoir properties have usually low efficiency. However, in the case of unconventional sources, which include the oil source rocks of shales and coal, it is often impossible to carry out laboratory experiments because of their ruined state. In this regard, there is a necessity of application of new technologies to study the structure of pore space and evaluate reservoir properties of these rocks. One of these methods is currently the X-ray tomography. This method allows visualization of pore space of the test sample, to obtain its quantitative characterization of: the number and size of pores in it, their specific surface area and many other parameters that need to be considered in the development of hydrocarbon deposits. The paper demonstrates the possibility of X-ray tomography as an example of unconventional hydrocarbon sources – source rock Khadum suites and coal.

14

The Determination Of Diffusive Tortuosity In Concrete Specimens Using X-Ray Microtomography

Ranachowski Z., Jóźwiak-Niedźwiedzka D., Ranachowski P., Dąbrowski M., Kudela Jr. S., Dvorak T.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2A

1115--1119

EN

The paper presents a method of pore connectivity analysis applied to specimens of cement based composites differing in water to cement ratio. The method employed X-ray microtomography (micro-CT). Microtomography supplied digitized three-dimensional radiographs of small concrete specimens. The data derived from the radiographs were applied as an input into the application based on the algorithm called ‘random walk simulation’. As the result a parameter called diffusive tortuosity was established and compared with estimated porosity of examined specimens.

PL

Artykuł prezentuje metodę wyznaczania parametru charakteryzującego intensywność połączeń mikroporów w zastosowaniu do próbek kompozytów z matrycą cementową, różniących się stosunkiem wodnocementowym. Metoda bazuje na wynikach badań z zastosowaniem mikrotomograﬁi rentgenowskiej. Analizowano zdigitizowane zestawy danych, opisujące trójwymiarową reprezentację mikrostruktury niewielkich próbek wykonanych z betonu. Przygotowane w ten sposób skany mikrostruktury zastosowano jako dane wejściowe wprowadzone do oprogramowania wykorzystujacego algorytm ‘przypadkowo migrujących cząstek wirtualnych’. W ten sposób wyznaczono parametr mikrostruktury znany jako krętość dyfuzyjna. Parametr ten porównano z porowatością obserwowaną wyznaczoną dla zbadanych próbek przy wykorzystaniu analizy jasności voxeli w analizowanych próbkach.

15

Three Dimensional Morphology of β-Al5FeSi Intermetallics in AlSi Alloys

Mikołajczak P., Ratke L.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 1

47--50

EN

Iron is the most common and detrimental impurity in casting alloys and has been associated with many defects. The main consequence of the presence or adding of iron to AlSi alloys is the formation Fe-rich intermetallics with especially deleterious β-Al5FeSi. β-Al5FeSi phases are most often called needles on 2D micro sections, whilst platelets in 3D geometry. The x-ray tomography results have demonstrated Fe-rich phases with shapes different from simple forms such as needles or platelets and presented bent and branched phases. β grown as complicated structure of bent and branched intermetallics can decrease feeding ability, strengthen pores nucleation and eutectic colonies nucleation leading to lower permeability of mushy zone and porosity in the castings.

16

Monte Carlo calculated CT numbers for improved heavy ion treatment planning

Qamhiyeh S., Wysocka-Rabin A., Jäkel O.

Nukleonika

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2014

|

Vol. 59, No. 1

15--23

EN

Better knowledge of CT number values and their uncertainties can be applied to improve heavy ion treatment planning. We developed a novel method to calculate CT numbers for a computed tomography (CT) scanner using the Monte Carlo (MC) code, BEAMnrc/EGSnrc. To generate the initial beam shape and spectra we conducted full simulations of an X-ray tube, filters and beam shapers for a Siemens Emotion CT. The simulation output files were analyzed to calculate projections of a phantom with inserts. A simple reconstruction algorithm (FBP using a Ram-Lak filter) was applied to calculate the pixel values, which represent an attenuation coefficient, normalized in such a way to give zero for water (Hounsfield unit (HU)). Measured and Monte Carlo calculated CT numbers were compared. The average deviation between measured and simulated CT numbers was 4 ± 4 HU and the standard deviation σ was 49 ± 4 HU. The simulation also correctly predicted the behaviour of H-materials compared to a Gammex tissue substitutes. We believe the developed approach represents a useful new tool for evaluating the effect of CT scanner and phantom parameters on CT number values.

17

Investigating porosity of sintering porous copper structure with 3D micro-focus X-ray computed tomography (μCT)

Depczyński W.

Journal of Achievements in Materials and Manufacturing Engineering

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2014

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Vol. 66, nr 2

67--72

EN

Purpose: The paper presents studies on the structure intended to form a heat exchange element made of sintered porous Cu. Design/methodology/approach: Analyses of Cu foam exhibiting a cellular structure have been carried out using X-ray tomography. Findings:Samples of copper foam have been imaged at high resolution using a large-field, 3D micro-focus X-ray computed tomography (μCT) system, three-dimensional image blocks derived from the scans were examined as cross-sections along orthogonal planes and as perspective images, maneuvered to be viewed from any angle. Research limitations/implications: This work presents methods for obtaining pore size distributions for both the micro-pores and their interconnects. It‘s a matter of great significance for recognition of real structure of sintered porous elements and it’s utility mainly as heat transfer. Originality/value: The proposed X-ray method appears to be an excellent tool for determining the 3D structure of the sintered Cu foam. It should be used to improve changes detection in the structure of the foam itself, incurred to the effect of changes process appeared during heat transfer operation.

18

Application of X-Ray Microtomography and Optical Microscopy to Determine the Microstructure of Concrete Penetrated by Carbon Dioxide

Ranachowski Z., Jóźwiak-Niedźwiedzka D., Ranachowski P., Rejmund F., Dąbrowski M., Kudela S. jr., Dvorak T.

Archives of Metallurgy and Materials

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2014

|

Vol. 59, iss. 4

1441--1447

EN

In the paper two advanced methods for testing cement based composites are described and compared. These are X-ray microtomography and optical microscopy. Microtomography supplies three-dimensional images of small concrete specimens. In the tomograms all cracks, pores and other voids and inclusions, that exceed a few micrometers, are shown. Such visualisation can become a valuable tool for analysis of the basic material properties. Images obtained on thin sections and analysed with various methods on optical microscopes supply additional information on material microstructure that cannot be obtained in tomograms. For example it is relatively easy to determine zone penetrated by CO2 ingress. These two methods, presented on examples of tests, complete each another in order to supply a set of information on composition and defects of tested composite materials.

PL

W artykule przedstawiono dwie nowoczesne metody analizy struktury materiałów kompozytowych ze spoiwem na bazie cementu. Są to mikrotomografia komputerowa oraz optyczna analiza cienkich szlifów. Mikrotomografia pozwala na uzyskanie trójwymiarowych obrazów niewielkich próbek betonowych. Na tomogramach widoczne są układy rys, porów i innych pustek, których wymiary przekraczają kilka mikrometrów. Przestawienie tych obiektów w przestrzeni jest ważnym narzędziem do analizy podstawowych właściwosci materiału. Obrazy uzyskane na cienkich szlifach w mikroskopie optycznym, analizowane następnie różnymi metodami, dostarczają dodatkowych informacji o mikrostrukturze materiału, które nie mogą być dostrzeżone na tomogramach. Stosunkowo łatwo jest np. uzyskac obrazy stref skarbonatyzowanej matrycy cementowej. Obie przedstawione metody uzupełniają się wzajemnie i pozwalają na otrzymanie zbioru informacji o składzie i defektach badanych materiałów kompozytowych.

19

Influence of Wax Pattern Surface Quality on Prime Coat of Ceramic Mold

Bałkowiec A., Wawulska P., Matysiak H., Rabajczyk A., Smektała P., Zdunek J., Kurzydłowski K.

Archives of Foundry Engineering

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2014

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Vol. 14, iss. 1 spec.

67--72

EN

The authors have made an attempt to enrich the knowledge about the influence of wax pattern washing process and its influence on the quality of the shell prime coat. Two types of wax were investigated: A7Fr/60 and KC2690. A7Fr60 is used for pattern fabrication, while KC2690 is typical sprue wax. The goal of work was to establish wax solubility accuracy in Trisol 60 Plus and Houghto Clean 530 versus time and influence of dipping time to wax samples surface quality. Additionally, after exposition of wax samples, their surface morphology was characterized with the use of laser profilometry and surface roughness measurement. The quality of formed prime coat was established by X-ray tomography. The measurement of wetting angle of the wax by binder was conducted. The results have shown that the main factor which influences the quality of the prime coat is surface wettability rather than wax surface roughness.

20

X-ray tomography investigation of Fe-rich intermetallics in AlSi alloys

Mikołajczak P., Ratke L.

Archives of Foundry Engineering

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2013

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Vol. 13, iss. 4

79--82

EN

Iron exists as a common impurity element in AlSi foundry alloys. The main consequence of the presence or adding of iron to AlSi alloys is the formation Fe-rich intermetallics with especially deleterious β-Al5FeSi. This work aims to identify the role of fluid flow on the microstructure and intermetallics in Al-9 wt.% Si-0.2/0.5/1.0 wt.% Fe alloys directionally solidified under defined thermal and fluid flow conditions and extensively uses 3D x-ray tomography to get a better insight into their morphology and formation. The results have revealed the growth of larger and more dense β-Al5FeSi intermetallics in the specimen centre as an effect of forced flow. The reconstructions confirmed that the course of number density at the specimen cross section increases from the specimen edge to its centre.