Application of Computed Tomography in Structure Analyses of Metal Matrix Syntactic Foams

Kozma, István; Zsoldos, Ibolya; Dorogi, G.; Papp, S.-Z.

doi:10.7763/ijcte.2015.v7.989

“…The authors put ballast particles to a HDPE (water) tube (lined with single layer 1200 g/m 2 geotextile) with its original closing element and loaded by ZD-40 machine static to an ultimate loading value step by step. Before and after each loading stage, ballast samplewith all the particles in the tubeare scanned by a CT (computer tomography) equipment [7,10,11,25,26]. Because of loading a small aggregate, almost every particle's degradation is trackable.…”

Section: Purposementioning

confidence: 99%

“…Application of the CT (X-ray) equipment While there is a wide range of literature available for the 3-D image analysis, the authors found very little source related to testings of railway ballast and/or civil engineer granular materials with CT equipment. The CT (X-ray) equipment is available to the authors in the laboratory of Audi Hungaria Faculty of Automotive Engineering at Széchenyi István University, Győr (Hungary) [7,10,11,25,26].…”

Section: Individual Laboratory Testmentioning

confidence: 99%

Specific Evaluation Methodology of Railway Ballast Particles’ Degradation

Juhász

¹

,

Fischer

²

2019

STP

4

0

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Purpose. The most railway lines in the world have so called traditional ballasted superstructure. The authors think that it is important to learn about the process of ballast degradation. There are only two types of standardized laboratory test methods in the EU to assess railway ballast particle degradation and describe the rock physic characteristics, but are not suitable for modelling the railway stress-strain circumstances of ballast materials, and they particles. In this paper the authors represent some conclusions from their research that the authors experienced during their individual fatigue laboratory test and from new additional tests. With these kind of testing methods, the deterioration process of railway ballast particles can be assessed more realistic and precisely. Methodology and new directions. There are two types of laboratory tests which are presented in this article. The first one was performed by using a shear box with a special layer structure that is loaded by dynamic, pulsating force; while the second one was executed by using a 140 mm diameter HDPE tube with its original closing element that is loaded by ZD-40 machine. Findings and problems. There is a development after the R&D work made and published in 2014, in 2017 and 2018 years the ballast particle deterioration process is given according to more intermediate fatigue cycles with individual measurements that show more precise «picture» about the full particle degradation, i.e. breakage process. The authors give more accurate correlation functions between the calculated parameters and load cycles during fatigue. However, there are many factors in the test that need to be improved in the future. Therefore, the authors have discovered other additional tests. Originality. The most important goal of the authors that supplement the currently used regulation with new measurement methods. Practical value The authors' developed and new methods may serve as a basis for a future instruction or regulation. The publishing of this paper was supported by EFOP 3.6.1-16-2016-00017 project.

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“…Пено-металл обладает пористостью порядка 75-95 % [10], а его плотность в несколько раз ниже, чем у литого металла. По сути пенометалл -это одно-временно и новый вид конструкции, и новый вид спеченного материала [12].…”

Section: Introductionunclassified

The contact-free evaluation of porosity of nickel foam by 3D X-ray tomography

Игнатова

¹

,

Ignatov

²

2016

Russ. J. Non-ferrous Metals

0

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Исследована макроструктура пеноникеля пористостью 20, 30, 45 и 60 ppi методом рентгеновской томографии при напряже-нии U = 300 кВ, токе I = 300 мА, времени экспозиции t exp = 354 мс; число кадров составляло 2500 шт. Установлено, что реальные параметры пор отклоняются от теоретических. Показано, что чем выше пористость, тем равномернее размер пор. Рентгенов-ская томография позволяет оценивать такой показатель, как толщина стенки между порами, который ранее не учитывался. Выявлено, что однородность по размерам толщины стенок снижается по мере повышения пористости образца. Представ-ленные результаты позволяют рекомендовать рентгеновскую томографию как метод исследования и контроля пеноматери-алов, порошков и различных спеченных материалов, а полученные данные могут быть использованы для создания реальных трехмерных моделей.Ключевые слова: рентгеновская томография, пеноникель, макростроение, пористость, неразрушающий контроль. Contact-Free Evaluation of Porosity of Nickel Foam by 3D X-Ray TomographyMacrostructure of nickel foam with porosity of 20, 30, 45, and 60 ppi is investigated by X-ray tomography at voltage U = 300 kV, current I = 300 mA, and exposure time t exp = 354 ms is investigated; the number of frames was 2500. It is established that actual parameters of pores deviate from theoretical ones. It is shown that the higher porosity is, the more uniform the pore-size distribution is. The X-ray tomography makes it possible to evaluate such characteristic as the thickness of the wall between the pores, which was not taken into account previously. It is revealed that the uniformity of the wall thickness with respect to sizes decreases as the sample porosity increases. These results make it possible to recommend the X-ray tomography as the method for the investigation and monitoring the foam materials and powders in various sintered materials, and the acquired data can be used to create actual three-dimensional models.Keywords: X-ray tomography, nickel foam, macrostructure, porosity, nondestructive monitoring.

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“…Пенометалл обладает пористостью порядка 75-95 % [10], а его плотность в несколько раз ниже, чем у литого металла. По сути пенометалл -это одновременно и новый вид конструкции, и новый вид спеченного материала [12].…”

Section: Introductionunclassified

Contact-Free Evaluation of Porosity of Nickel Foam by 3D X-Ray Tomography

Игнатова¹,

Ignatov²

2015

Izv. VUZ. Poroshk. Met.

0

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Исследована макроструктура пеноникеля пористостью 20, 30, 45 и 60 ppi методом рентгеновской томографии при напряже-нии U = 300 кВ, токе I = 300 мА, времени экспозиции t exp = 354 мс; число кадров составляло 2500 шт. Установлено, что реальные параметры пор отклоняются от теоретических. Показано, что чем выше пористость, тем равномернее размер пор. Рентгенов-ская томография позволяет оценивать такой показатель, как толщина стенки между порами, который ранее не учитывался. Выявлено, что однородность по размерам толщины стенок снижается по мере повышения пористости образца. Представ-ленные результаты позволяют рекомендовать рентгеновскую томографию как метод исследования и контроля пеноматери-алов, порошков и различных спеченных материалов, а полученные данные могут быть использованы для создания реальных трехмерных моделей.Ключевые слова: рентгеновская томография, пеноникель, макростроение, пористость, неразрушающий контроль. Contact-Free Evaluation of Porosity of Nickel Foam by 3D X-Ray TomographyMacrostructure of nickel foam with porosity of 20, 30, 45, and 60 ppi is investigated by X-ray tomography at voltage U = 300 kV, current I = 300 mA, and exposure time t exp = 354 ms is investigated; the number of frames was 2500. It is established that actual parameters of pores deviate from theoretical ones. It is shown that the higher porosity is, the more uniform the pore-size distribution is. The X-ray tomography makes it possible to evaluate such characteristic as the thickness of the wall between the pores, which was not taken into account previously. It is revealed that the uniformity of the wall thickness with respect to sizes decreases as the sample porosity increases. These results make it possible to recommend the X-ray tomography as the method for the investigation and monitoring the foam materials and powders in various sintered materials, and the acquired data can be used to create actual three-dimensional models.Keywords: X-ray tomography, nickel foam, macrostructure, porosity, nondestructive monitoring.

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Application of Computed Tomography in Structure Analyses of Metal Matrix Syntactic Foams

Cited by 6 publications

References 18 publications

Specific Evaluation Methodology of Railway Ballast Particles’ Degradation

Specific Evaluation Methodology of Railway Ballast Particles’ Degradation

The contact-free evaluation of porosity of nickel foam by 3D X-ray tomography

Contact-Free Evaluation of Porosity of Nickel Foam by 3D X-Ray Tomography

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