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1

Technology of Production of Mold Filling Material for Specific Purposes in the Field of Metallic Foam Casting

Kroupová Ivana, Bašistová Martina, Lichý Petr, Merta Václav, Radkovský Filip, Jezierski Jan

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 2

757--763

EN

This paper describes the technology for the production of precursors (space holder material) used to form the complex internal structure of cast metal foam. The precursor material must exhibit sufficient refractoriness, resist contact with liquid metal and at the same time should exhibit good collapsibility after casting. With regard to the greening of foundry production, the focus of this paper was on materials that could exhibit the above properties and at the same time do not have a negative impact on the environment. In this paper, the technology for the production of spherical precursors from a self-hardening mixture with a geopolymer-based binder system is described and verified. The motivation for the choice of material and all the sub-steps of the process - molding into the core box, tumbling, including the necessary accompanying tests of the mechanical properties of the core mixture being verified - are described.

2

Peridynamic Simulation of Crushing Processes in Copper Open-Cell Foam

Postek E., Pęcherski R. B., Nowak Z.

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 4

1603--1610

EN

In the last 20 years, a new meshless computational method has been developed that is called peridynamics. The method is based on the parallelized code. The subject of the study is the deformation of open-cell copper foams under dynamic compression. The computational model of virtual cellular material is considered. The skeleton structure of such a virtual cellular material can be rescaled according to requirements. The material of the skeleton is assumed as the oxygen free high conductivity (OFHC) copper. The OFHC copper powder can be applied in additive manufacturing to produce the open-cell multifunctional structures, e. g., crush resistant heat exchangers, heat capacitors, etc. In considered peridynamic computations the foam skeleton is described with the use of an elastic-plastic model with isotropic hardening. The dynamic process of compression and crushing with different impact velocities is simulated.

3

Preparation and Evaluation of Properties of Cast Metallic Foams with Regular Inner Structure

Lichý P., Elbel T., Kroupová I., Radkovský F.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 3

1643--1646

EN

Lately we encounter still more new applications of metallic foams, as well as possible methods of their manufacture. These metallic materials have specific properties, such as large rigidity at low density, in some cases high thermal conductivity, capability to absorb energy, etc. The work is focused on the preparation of these materials using conventional casting technology, which ensures rapid and economically feasible method for production of shaped components. In the experimental part we studied conditions of casting of metallic foams with a regular structure made of ferrous and non-ferrous alloys. For thus obtained castings we evaluated the achieved microstructure and mechanical properties, which determine the possible use of these materials. The samples were subjected to compression tests, by which we investigated deformation behaviour of selected materials and determined the value of energy absorption.

4

Struktura, wytwarzanie i zastosowanie pian stałych

Gancarczyk A., Piątek M., Iwaniszyn M., Kryca J., Leszczyński B., Łojewska J., Kołodziej A.

Przemysł Chemiczny

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2015

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T. 94, nr 10

1821-1824

PL

Piany stałe są obecnie produkowane z różnorodnych materiałów (metal, ceramika, tworzywa sztuczne, węgiel, szkło). Przedstawiono przegląd pian dostępnych na rynku, różne metody ich produkcji, zastosowania oraz potencjalne możliwości wykorzystania. Szczególną uwagę zwrócono na morfologię pian jako na jeden z głównych parametrów, których znajomość jest niezbędna przy ich badaniach, a następnie zastosowaniu.

EN

A review, with 28 refs., of the available on the market solid foams made of metals, ceramics, polymers, C1 and glass.

5

Piany metalowe jako alternatywny nośnik katalizatora w silnie egzotermicznych procesach utleniania katalitycznego

Dyga R., Witczak S., Gancarczyk A., Piątek M., Jaroszyński M., Łojewska J., Kołodziej A.

Przemysł Chemiczny

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2015

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T. 94, nr 10

1825-1827

PL

Przeprowadzono badania oporów przepływu i współczynników wnikania ciepła dla przepływu powietrza przez rurę wypełnioną pianami stałymi, rozważanymi jako nośnik katalizatora w egzotermicznych procesach selektywnego utleniania. Stwierdzono intensywny transport ciepła i niewielkie opory przepływu. Oceniono piany stałe jako obiecujący nośnik katalizatora w rozważanych procesach.

EN

Flow resistance and heat transfer were studied in an air flow through a tube filled with solid foams. The foams were recommended as catalyst carriers for the exothermic oxidn.

6

Design of micro porous Al foams by high energy milling

Robert M. H., Silva R. R.

Archives of Materials Science and Engineering

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2015

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Vol. 71, nr 1

5--15

EN

To explore a new route to produce metallic foams which results in a structure of closed micro porous. High energy milling is employed to incorporate particles of foaming agents in metallic powders to promote homogeneous distribution of micro gas bubbles during foaming. Design/methodology/approach: AA2014 powders were mixed with TiH2 particles as gas releasing agent, through high energy milling, producing composite powders. Powders were compacted and obtained compacted precursors were heated to promote foaming of the metal. Effect of processing conditions in the expansion of the metal, structural characteristics, density and mechanical properties under compression, of obtained foams was analyzed. Findings: Foaming composite powders of AA2014/TiH2 produced by high energy milling is a promising route to produce micro porous aluminium foams. The best foaming condition among the conditions investigated, occurs for the highest milling time (17 h) and highest heating rate (3°C/s) imposed during foaming, resulting in 140% of maximum expansion and foams with relative density of 0.44. Research limitations/implications: Main limitation of the proposed process is the long time required to produce composite powders by high energy milling, which can justify the process for specific purposes where micro porous are required. However, as all new development, further works can lead to the optimization of processing parameters, mainly concerning reduction of processing time, to make the process compatible to wider industrial applications. Practical implications: New products can be developed for specific applications requiring porous with micro scale. Originality/value: The use of the foaming agent structurally incorporated in the metal powder to produce precursors for foaming is original.

7

Methods of production of metallic foams

Stręk A. M.

Przegląd Mechaniczny

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2012

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nr 12

36--39

PL

W artykule zaprezentowano współcześnie stosowane metody wytwarzania pian metalicznych. Przedstawiono podział porowatych materiałów metalicznych i ogólną klasyfikację metod ich produkcji, ze szczególnym uwzględnieniem metod prowadzących do wytworzenia pian. Omówiono także trudności i korzyści związane ze stosowaniem poszczególnych metod, a także kierunki rozwoju technologii wytwarzania pian metalicznych.

EN

This paper discusses manufacturing methods of metal foams. The introduction briefly presents a division of porous metallic materials and an overall classification of methods for their production, with particular emphasis on methods leading to produce foam structures. The main part of the paper describes production techniques in detail. The paper also includes information on difficulties and benefits of particular methods, as well as on the development opportunities for manufacturing technologies of metallic foams.

8

Processing, stabilization and applications of metallic foams. Art of science

Srivastava V. C., Sahoo K. L.

Materials Science Poland

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2007

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Vol. 25, No. 3

733--753

EN

Metallic foams have been of considerable interest both from the industrial applicability and scientific viewpoint. In the last three decades, since the inception of the metal foam, several processes have been developed to introduce large size pores, almost uniformly distributed, in the metallic materials. These processes include liquid metal route, powdered metal technique and some other methodologies in which pores are incorporated by direct sintering of foamed elements. Metallic foams have seen tremendous innovations for the last few years and efforts are being made to achieve foams with a low cost and with reliable properties. The stability of cell structure during the foaming process has also been a concern for researchers. Therefore, methods have been explored to increase the stability by introduction of ceramic particles in the material to be foamed, addition of alloying elements, secondary processing of precursor materials, and by optimizing the process parameters. To this end, experiments have also been made in microgravity conditions to study the mechanism of foam formation which can give a better understanding for controlling the processing conditions. Despite the current development, there are several limitations for a wide applicability of metallic foams in various industrial sectors, such as high cost of production, variability in measured properties, and unavailability of reliable testing methods. Taking these facts into consideration, the present paper is aimed at reviewing various foam processing techniques, the measures required to be taken for making stable foams and the industrial applications of the metallic foams in the current state of development.

9

Validation of numerical models of metallic foams from the aspect of energy absorption

Włodarczyk J., Niezgoda T., Barnat W., Dziewulski P.

Journal of KONES

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2007

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Vol. 14, No. 2

561-569

EN

The main objective of the paper is to assess the energy absorbing capabilities of metallic foams. The results of experimental investigation of energy absorbing capabilities for three metallic foams under kinematic loading are presented. The tests were conducted on the INSTRON Dynamic Testing System. The numerical computations were carried out using the LS DYNA code. For metallic foam modelling, MAT_26 (MAT_HONEYCOMB) was used; it is normally used for "honeycombs" and anisotropic foams modelling. For numerical calculations, two types of numeric elements were used: SOLIDE and Plate types. SOLID type elements were used for foam modelling, and Schell types -for charge definition. A numeric diagram is presented on drawing 10. As in the case of real tested elements, the foam element was charged by a plate of velocity of 5 m/s. The metallic foam was checked in Mechanics and Applied Informatics Faculty of Military University of Technology. Tests were made on INSTRON resistance machine. The charge was made using cinematic input function. Presented results are preliminary one, the experiment was made in order to choose a foam material having the best energy absorption characteristics. The conclusion of preliminary estimation of obtained results is that the samples with the smallest pores have the most important energy absorption level. Nevertheless, the following stage of the works should be impact resistance tests: deceleration test in the aspect of security improvement.

PL

Głównym celem pracy była ocena zdolności pochłaniania energii przez piany metaliczne. W niniejszym artykule przedstawiono wyniki eksperymentalnych badań energochłonności trzech pian metalicznych obciążonych przemieszczeniem. Analizę numeryczna pianki metalicznej przeprowadzono w oprogramowaniu LS DYNA. Do modelowania piany metalicznej zastosowano MAT_26 (MAT_ HONEYCOMB) który jest używany głównie do modelowania "plastrów miodu" i pianek z właściwościami anizotropowymi. Do obliczeń numerycznych wykorzystano dwa rodzaje elementów numerycznych: typu SOLID i Plate. Elementy typu SOLID były wykorzystywane do modelowania pianki a typu Schell wykorzystywano do zdefiniowania obciążenia. Model numeryczny przedstawiono na rys. 10. Element piankowy został podobnie jak w przypadku badanych obiektów rzeczywistych obciążony płytą poruszającą się z prędkością 5 m/s. Pianę metaliczną przebadano w Katedrze Mechaniki i Informatyki Stosowanej WAT. Badania przeprowadzono na maszynie wytrzymałościowej INSTRON. Obciążenie realizowano przez wymuszenie kinematyczne. Przedstawione wyniki są wstępnymi, eksperyment został przeprowadzony w celu wybrania materiału piankowego o największej energochłonności. Na podstawie wstępnej oceny uzyskanych wyników można powiedzieć, że próbki z najmniejszymi porami posiadają największą energochłonność. Jednakże kolejnym etapem prac powinny być badania udarnościowe pomiaru opóźnień w aspekcie zwiększenia bezpieczeństwa.

10

Manufacturing of cellular A2011 alloy from semi-solid state

Robert M. H., Delbin D.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 24, nr 1

115-122

EN

Purpose: The work presents a new method to produce cellular metallic material by pressing the alloy in the thixotropic semi-solid state into a layer of space holder particles, which are removed from the product after the forming operation. Design/methodology/approach: It is investigated the influence of the thixoforming temperature and the size of space holder particles, in the ability of penetration of the slurry in the porous preform as well as the structure of the obtained porous material (general aspect, quantitative and qualitative characterization of porosity microstructure of cells walls and density of the product). Findings: Cylindrical samples presenting three different ranges of porosity were produced. The cellular material obtained contains open porosity, being characterized as sponge. Products were analyzed by tomography and metallographic techniques. Results show that the proposed process is able to produce acceptable porous material, in a simple and low cost technique. The quality of the product depends rather on the processing temperature than on the size of space holder particles. Low liquid fraction in the thixotropic slurry can lead to incomplete infiltration and deformation of the preform. In the analyzed conditions influence of the size of space holder particles could be observed neither in the processing ability nor in the quality of the product. Density of produced porous material increases as processing temperature increases, due to the increase of cells walls thickness. Research limitations/implications: The investigated process is suitable only for alloys with a significant solidification range. Practical implications: The new method to produce cellular metals can represent energy savings and is highly operational when compared to conventional methods based on liquid infiltration, since lower temperatures are involved and no need of liquid handling is required. Originality/value: the process proposed is a new one; no techniques based on thixoforming of the alloy into porous preforms are known so far.

11

Metallic foams - ultra light materials for structural applications.

Simancik F.

Inżynieria Materiałowa

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2001

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R. XXII, nr 5

823-828

EN

Metallic foams are relatively unknown structural materials, however with enormous future potential for applications where lightweight combined with high stiffness and acceptable manufacturing costs are of prime interest. The performance of metallic foams, in particular those made of aluminium, in various prototypes, such as foamed panels, sandwiches, complex 3-D parts, foamed hollow profiles as well as castings with foamed cores, has been discussed with respect to the expected and achieved goals. The important contributions of aluminium foam to the improvement of the product's properties are highlighted and most promising utilisation is suggested.

12

Metallic foams on the example of composite structures

Sobczak J.

Archiwum Technologii Maszyn i Automatyzacji

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2001

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Vol. 21, Nr spec

161-169

EN

Metallic foams are ultra light weight engineered materials designed for special properties which can be used in many industrial applications. The development of new highly porous structures can be a relevant challenge for materials scientists. This overview discussed manufacturing practices, structure, properties, and application of composite and syntactic foams, some of which were produced at Foundry Research Institute, Krakow. The results of mechanical properties for large amount of metallic foams produced by different techniques in relation to their density are also highlighted. New kind of highly porous structures can fill up the lack of properties between currently produced cellular solids and metals, alloys and metal matrix composites.

PL

Piany metalowe należą do ultra lekkich rozwiązań materiałowych zaprojektowanych w celu uzyskania odpowiedniego kompleksu właściwości, przydatnych w wielu zastosowaniach przemysłowych. Oprócz aspektów utylitarnych, badania struktur porowatych (komórkowych) odkrywają nowe możliwości poznawczo-interpretacyjne w inżynierii materiałowej. W artykule omówiono aspekty technologiczne wytwarzania pian kompozytowych (zbrojonych cząsteczkami ciała stałego lub gazem) i syntaktycznych (z pustymi sferami), ich specyfikę strukturalną, właściwości i potencjalne obszary zastosowań. Przedstawiono szereg rozwiązań technologiczno-materiałowych, opracowanych w Instytucie Odlewnictwa w Krakowie. Na przykładzie dużej populacji pian metalowych przeanalizowano korelacje pomiędzy ich właściwościami mechanicznymi, gęstością i sposobami wytwarzania. Stwierdzono, że nowe rodzaje struktur porowatych wpisują się w swoiste kontinuum właściwości pomiędzy aktualnie wytwarzanymi strukturami komórkowymi a metalami i stopami monolitycznymi oraz metalowymi materiałami kompozytowymi.