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1

Thermal characterization of halloysite materials for porous ceramic preforms

Kujawa M., Suwak R., Dobrzański L.A., Gerle A., Tomiczek B.

Archives of Materials Science and Engineering

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2021

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Vol. 107, nr 1

5--15

EN

Purpose: The aim of the study was to investigate the possibility of sintering raw (natural) halloysite and pure halloysite to produce porous ceramic preforms, and determination of sintering temperature based on the results of investigations into thermal effects, linear changes and phase transitions. Design/methodology/approach: Due to mullitisation ability of halloysite at high temperature, alternative applications based on the sintering technology (including the production of reinforcement of metal matrix composites) are being searched for. Pure halloysite and Dunino halloysite were selected for the study. Findings: Pure halloysite, characterized by low impurities, dimensional stability during sintering, softening temperature above 1500ºC and ability to transform into mullite at temperatures above 950ºC could be used as a base for the production of sintered, porous mullite preforms. Research limitations/implications: Presence of impurities in Dunino halloysite, contribute to the shift of the sintering temperature towards lower temperatures and caused a rapid and uncontrolled shrinkage of the sample and the appearance of the softening temperature at 1300ºC. Practical implications: Based on the research of thermal (DTA/TG, linear changes in high-temperature microscopy) and XRD studies it is possible to determine the sintering temperature of pure halloysite to manufacture the porous mullite preforms with open porosity. Originality/value: The received results show the possibility of obtaining the new mullite preforms based on pure halloysite.

2

Technologie infiltracji

Kremzer M., Tomiczek B., Matula G.

LAB Laboratoria, Aparatura, Badania

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2018

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R. 23, nr 4

43--48

3

Metody badań proszków

Matula G., Tomiczek B., Kremzer M., Przybyła M.

LAB Laboratoria, Aparatura, Badania

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2018

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R. 23, nr 4

16--19

4

Application of Ceramic Injection Moulding and Pressure Infiltration to the Manufacturing of Alumina/AlSi10Mg Composites

Matula G., Krzysteczko-Witek J., Tomiczek B.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 4

2101--2106

EN

Ceramic injection moulding and gas pressure infiltration were employed for the manufacturing of alumina/AlSi10Mg composites. Porous ceramic preforms were prepared by mixing alumina powder with a multi-binder system and injection moulding of the powder polymer slurry. Then, the organic part was removed through a combination of solvent and thermal debinding, and the materials were finally sintered at different temperatures. The ceramic preforms manufactured in this way were infiltrated by an AlSi10Mg alloy. The microstructure and properties of the manufactured materials were examined using scanning electron microscopy, mercury porosimetry and bending strength testing. The results of transmission electron microscopy and scanning electron microscopy observations show that the fabricated composite materials are characterised by the percolation type of the microstructure and a lack of unfilled pores with good cohesion at the metal-ceramic interfaces. This is surprising considering that over 30% of the pores are smaller than 1 μm. The results show that the bending strength of the obtained composites decreased with increasing sintering temperature of the porous preforms.

5

The Influence of the Dispersion Method on the Microstructure and Properties of MWCNTs/AA6061 Composites

Dobrzański L. A., Macek M., Tomiczek B., Nuckowski P. M., Nowak A. J.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 2B

1229--1234

EN

The aim of this work was to study the effect of different methods of multi-walled carbon nanotubes (MWCNTs) dispersion, and their influence on the microstructure and properties of aluminium alloy matrix composites produced using the powder metallurgy techniques, such as powder milling/mixing and hot extrusion. The main problem in the manufacturing of nanocomposites is the homogeneous distribution of MWCNTs in the metal matrix. To achieve their proper distribution a high-energy and low-energy mechanical milling, using a planetary ball mill, and mixing, using a turbulent mixer, were applied. Studies have shown that composite materials prepared using milling and extrusion have a much better dispersion of the reinforcing phase, which leads to better mechanical properties of the obtained rods. The low-energy mechanical mixing and mixing using the turbulent mixer neither change the powder morphology nor lead to adequate dispersion of the carbon nanotubes, which directly affects the resulting properties.

6

Testing of flame sprayed Al2O3 matrix coatings containing TiO2

Czupryński A., Górka J., Adamiak M., Tomiczek B.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 3

1363--1370

EN

The paper presents the results of the properties of flame sprayed ceramic coatings using oxide ceramic materials coating of a powdered aluininiuni oxide (Al2O3) matrix with 3% titanium oxide (TiO2) applied to unalloyed S235JR grade structural steel. A primer consisting of a metallic Ni-Al-Mo based powder has been applied to plates with dimensions of 5X200X300 mm and front surfaces of ø40x50 mm cylinders. Flame spraying of primer coating was made using a RotoTec 80 torch, and an external coating was made with a CastoDyn DS 8000 torch. Evaluation of the coating properties was conducted using metallographic testing, phase composition research, measurement of microhardness, substrate coating adhesion (acc. to EN 582:1996 standard), erosion wear resistance (acc. to ASTM G76-95 standard), and abrasive wear resistance (acc. to ASTM G65 standard) and thermal impact. The testing performed has demonstrated that flame spraying with 97% Al2O3 powder containing 3% TiO2 performed in a range of parameters allows for obtaining high-quality ceramic coatings with thickness up to ca. 500 μni on a steel base. Spray coating possesses a structure consisting mainly of aluminium oxide and a small amount of NiAl10O16 and NiAl32O49 phases. The bonding primer coat sprayed with the Ni-Al-Mo powder to the steel substrate and external coating sprayed with the 97%Al2O3 powder with 3% TiO2 addition demonstrates mechanical bonding characteristics. The coating is characterized by a high adhesion to the base amounting to 6.5 MPa. Average hardness of the external coating is ca. 780 HV. The obtained coatings are characterized by high erosion and abrasive wear resistance and the resistance to effects of cyclic thermal shock.

7

Properties of the Aluminium Alloy EN AC-51100 after Laser Surface Treatment

Tański T., Pakieła W., Janicki D., Tomiczek B., Król M.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 1

199--204

EN

In this paper, the influence of a laser surface treatment on the structure and properties of aluminium alloy has been determined. The aim of this work was to improve the tribological properties of the surface layer of the EN AC-51100 aluminium alloy by simultaneously melting and feeding silicon carbide particles into the molten pool. The silicon carbide powder was introduced into the liquid metal using a gravity feeder within a constant feed rate of 1 g/min. A high power diode laser (HPDL) was used for remelting. Laser beam energies used in experiments were 1.8 kW, 2.0 kW and 2.2 kW, combined with the constant velocity of 50 mm/min. As a result of the laser treatment on the aluminium alloy, a composite layer with greater hardness and wear resistance compared to the based material was obtained.

8

Manufacturing of Porous Ceramic Preforms Based on Halloysite Nanotubes (Hnts)

Kujawa M., Dobrzański L. A., Matula G., Kremzer M., Tomiczek B.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 2B

917--922

EN

The aim of this study was to determine the influence of manufacturing conditions on the structure and properties of porous halloysite preforms, which during pressure infiltration were soaked with a liquid alloy to obtain a metal matrix composite reinforced by ceramic, and also to find innovative possibilities for the application of mineral nanotubes obtained from halloysite. The method of manufacturing porous ceramic preforms (based on halloysite nanotubes) as semi-finished products that are applicable to modern infiltrated metal matrix composites was shown. The ceramic preforms were manufactured by sintering of halloysite nanotubes (HNT), Natural Nano Company (USA), with the addition of pores and canals forming agent in the form of carbon fibres (Sigrafil C10 M250 UNS SGL Group, the Carbon Company). The resulting porous ceramic skeletons, suggest innovative application capabilities mineral nanotubes obtained from halloysite.

9

Joining of the AMC Composites Reinforced with Ti3Al Intermetallic Particles by Resistance Butt Welding

Adamiak M., Tomiczek B., Górka J., Czupryński A.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 2A

847--852

EN

The introduction of new reinforcing materials continues to be investigated to improve the final behaviour of AMCs as well as to avoid some drawbacks of using ceramics as reinforcement. The present work investigates the structure, properties and ability of joining aluminium EN-AW 6061 matrix composite materials reinforced with Ti3Al particles by resistance butt welding as well as composite materials produced by mechanical milling, powder metallurgy and hot extrusion techniques. Mechanically milled and extruded composites show finer and better distribution of reinforcement particles, which leads to better mechanical properties of the obtained products. Finer microstructure improves mechanical properties of obtained composites. The hardness increases twice in the case of mechanically milled composites also, a higher reinforcement content results in higher particle dispersion hardening, for 15 wt.% of intermetallics reinforcement concentration composites reach about 400 MPa UTS. Investigation results of joints show that best hardness and tensile properties of joints can be achieved by altering soft conditions of butt welding process e.g. current flow time 1.2 s and current 1400 A. To improve mechanical properties of butt welding joints age hardening techniques can also be used.

10

Abrasive wear of AlSi12-Al2O3 Composite materials manufac tired by pressure infiltration

Kremzer M., Dziekońska M., Sroka M., Tomiczek B.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 3

1255-1260

EN

The aim of this study is to investigate tribological properties of EN AC-AlSi12 alloy composite materials matrix manufactured by pressure infiltration of Al2O3 porous preforms. In the paper, a technique of manufacturing composite materials was described in detail as well as wear resistance made on pin on disc was tested. Metallographic observations of wear traces of tested materials using stereoscopic and confocal microscopy were made. Studies allow concluding that obtained composite materials have much better wear resistance than the matrix alloy AlSil2. It was further proved that the developed technology of their preparation consisting of pressure infiltration of porous ceramic preforms can find a practical application.

11

Corrosion behaviour of aluminium matrix composites reinforced with sintered halloysite nanotubes

Dobrzański L. A., Reimann Ł., Kujawa M., Tomiczek B.

Journal of Achievements in Materials and Manufacturing Engineering

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2015

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Vol. 73, nr 2

92--99

EN

Purpose: The aim of this study was to determine the effect of mass fraction and sintering temperature of the halloysite nanotubes on the corrosion behavior of the infiltrated AlSi12 matrix composites, concerning the matrix alloy. Design/methodology/approach: The corrosion resistance research was done with a potentiodynamic method. Electrochemical corrosion research was made in water centre of 3% NaCl at room temperature. Electrochemical studies of corrosion resistance were performed by determine the open circuit potential and saving the anodic polarization curves by applying to potential changes in the direction of anode and cathode at 1 mV/s. Based on the registered anodic polarization curves were determined: corrosion potential, passive layer breakdown potential, corrosion current density, polarization resistance. The value of corrosion current was determined using the Tafel extrapolation. Findings: Mass fraction of the halloysite nanotubes does not affect the corrosion resistance of the composites as opposed to their sintering temperature. The increase in temperature of a 200°C resulted in a significant reduction in corrosion resistance, but it is still higher than the corrosion of the matrix material. Practical implications: The aluminium alloy matrix composites reinforced with sintered preforms made by sintering halloysite nanotubes are modern materials that could find application in the automotive industry. The mechanical properties are greater than the alloy matrix while retaining a low density. It was necessary to examine the corrosion resistance as one of the important properties of the composites which are exposed to corrosive environments. Originality/value: Beyond the articles of the authors, analysis of mechanical properties and corrosion resistance of the infiltrated AlSi12 matrix composites reinforced by preform made by sintered halloysite were not found in the available literature.

12

Effect Of Milling Time On Microstructure Of AA6061 Composites Fabricated Via Mechanical Alloying

Tomiczek B., Pawlyta M., Adamiak M., Dobrzański L. A.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2A

789--793

EN

The aim of this work is to determine the effect of manufacturing conditions, especially milling time, on the microstructure and crystallite size of a newly developed nanostructural composite material with the aluminium alloy matrix reinforced with halloysite nanotubes. Halloysite, being a clayey mineral of volcanic origin, is characterized by high porosity and large specific surface area. Thus it can be used as an alternative reinforcement in metal matrix composite materials. In order to obtain this goal, composite powders with fine microstructures were fabricated using high-energy mechanical alloying, cold compacting and hot extrusion techniques. The obtained composite powders of aluminium alloy reinforced with 5, 10 and 15 wt% of halloysite nanotubes were characterized with SEM, TEM and XRD analysis. It has been proven that the use of mechanical alloying leads to a high degree of deformation, which, coupled with a decreased grain size below 100 nm and the dispersion of the refined reinforcing particles–reinforces the material very well.

PL

Celem niniejszej pracy było określenie wpływu warunków wytwarzania, w szczególności czasu mielenia, na strukturę i wielkość krystalitów nowo opracowanych nanostrukturalnych materiałów kompozytowych o osnowie stopów aluminium wzmacnianych nanorurkami haloizytowymi. Haloizyt, będący minerałem ilastym pochodzenia wulkanicznego, charakteryzuje się dużą porowatością, dużą powierzchnią właściwą, i może stanowić alternatywne wzmocnienie metalowych materiałów kompozytowych. W tym celu przy użyciu wysokoenergetycznego mechanicznego stopowania w młynie kulowym wytworzono rozdrobnione i trwale połączone proszki kompozytowe, które następnie poddano zagęszczaniu na zimno i wyciskaniu na gorąco. Tak opracowane materiały kompozytowe o udziale masowym haloizytowego wzmocnienia 5, 10, 15% zbadano metodami skaningowej i transmisyjnej mikroskopii elektronowej oraz rentgenowskiej analizy fazowej. Stwierdzono, że wywołane mechanicznym stopowaniem silne odkształcenie plastyczne i zmniejszenie rozmiaru ziarna poniżej 100 nm oraz dyspersja haloizytowych cząstek wzmacniających wpłynęła na znaczne umocnienie materiałów kompozytowych.

13

Effect of Milling Time on Microstructure and Properties of AA6061/MWCNTS Composite Powders

Tomiczek B., Dobrzański L. A., Macek M.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 4

3029--3034

EN

The main purpose of this work is to determine the effect of milling time on microstructure as well as technological properties of aluminium matrix nanocomposites reinforced with multi-walled carbon nanotubes (MWCNTs) using powder metallurgy techniques, including mechanical alloying. The main problem of the study is the agglomeration and uneven distribution of carbon nanotubes in the matrix material and interface reactivity also. In order to reach uniform dispersion of carbon nanotubes in aluminium alloy matrix, 5÷20 h of mechanical milling in the planetary mill was used. It was found that the mechanical milling process has a strong influence on the characteristics of powders, by changing the globular morphology of as-received powder during mechanical milling process to flattened one, due to particle plastic deformation followed by cold welding and fracturing of deformed and hardened enough particles, which allows to obtain equiaxial particles again. The obtained composites are characterised by the structure of evenly distributed, disperse reinforcing particles in fine grain matrix of AA6061, facilitate the obtainment of higher values of mechanical properties, compared to the initial alloy. On the basis of micro-hardness, analysis has found that a small addition of carbon nanotubes increases nanocomposite hardness.

PL

Głównym celem podejmowanej pracy było określenie wpływu czasu mechanicznego mielenia na strukturę oraz własności technologiczne nanokompozytów o osnowie stopu aluminium 6061 wzmocnionych wielościennymi nanorurkami węglowymi (MWCNTs, ang. multi-walled carbon nanotubes) z wykorzystaniem technik metalurgii proszków, w tym mechanicznej syntezy oraz wyciskania na gorąco. Głównymi problemami podjętymi w badaniach były: aglomeracja i nierównomierny rozkład nanorurek węglowych w osnowie, a także reaktywność na granicy faz. W celu uzyskania jednorodnego rozmieszczenia nanorurek węglowych w osnowie stopu aluminium zastosowano wysokoenergetyczne mechaniczne mielenie w młynie planetarnym przez 5÷20 godzin. Stwierdzono, że zmiana czasu trwania procesu mechanicznej syntezy wpływa znacząco na morfologię materiałów proszkowych, umożliwiając uzyskanie zmiany ich morfologii ze sferycznej – charakterystycznej dla stanu wyjściowego – w odkształconą plastycznie (płatkową), następnie w powtarzających się procesach zgrzewania i pękania materiału umocnionego ponownie przyjmuje postać cząstek równoosiowych. Otrzymane w procesie mechanicznej syntezy materiały kompozytowe charakteryzują się strukturą równomiernie rozłożonych, rozdrobnionych cząstek fazy wzmacniającej, w drobnoziarnistej osnowie stopu AA6061, sprzyjających osiąganiu wyższych wartości własności wytrzymałościowych w porównaniu do stopu wyjściowego. Na podstawie badań mikrotwardości wykazano, że już niewielki dodatek nanorurek węglowych powoduje zwiększenie twardość nanokompozytu.

14

Influence of the milling time and MWCNT content on the wear properties of the AlMg1SiCu/MWCNT nanocomposites

Dobrzański L. A., Macek M., Tomiczek B., Pakieła W., Kremzer M.

Archives of Materials Science and Engineering

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2015

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Vol. 74, nr 2

77--84

EN

Purpose: In the present article, the wear behaviour of aluminium alloy matrix nanocomposites containing various amounts of carbon nanotubes (0, 2 and 5 vol.%) fabricated using powder metallurgy route has been investigated. Design/methodology/approach: In order to provide the uniform dispersion of the reinforcement particles in the aluminium matrix, in the study, mechanical milling has been used. Through a repeated process of cold welding, fracturing, and re-welding during the mechanical milling, carbon nanotubes are being well embedded between the deformed particles. The tribological test has been performed using a ball-on-plate wear tester. Findings: The microhardness testing has found that addition of carbon nanotubes increases nanocomposite hardness. The results of wear behaviour has showed the influence of the nanocomposite powders preparation conditions on the tribological properties of the final material. Practical implications: Nanocomposites reinforced with carbon nanotubes were prepared using powder metallurgy method what shows the practical implications of the manufacturing of nanocomposites. Originality/value: The results show that because of the simplicity and availability the technology of manufacturing can find the practical application in the production of new light metal matrix nanocomposites. It has been found out that carbon nanotubes, used as reinforcing phase have the influence on the properties of metal matrix composites.

15

EN AW-AlMg1SiCu alloy matrix composite materials reinforced with halloysite particles manufactured by mechanical milling

Dobrzański L. A., Tomiczek B., Pawlyta M., Gołombek K.

Inżynieria Materiałowa

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2014

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Vol. 35, nr 2

102--105

EN

In this work the selected results of microstructure investigations and mechanical properties of the aluminium matrix composite materials reinforced with halloysite particles manufactured by powder metallurgy techniques, including mechanical milling and pressing and hot extrusion following them, are presented. Composite materials were elaborated employing the air atomized powders of aluminium alloy EN AWAlMg1SiCu as a matrix and the halloysite nanotubes as a reinforcement. Composite powders of aluminium alloy matrix reinforced with 5, 10 and 15 wt % of halloysite nanotubes were manufactured by high-energy ball milling using a planetary mill. The obtained composite powders were compacted in the cylindrical matrix of 25 mm in diameter with pressure of 300 MPa and then extruded at 480°C with caning and without degassing. The microstructure of the investigated material was examined by the light microscope and scanning and transmission electron microscope. To determine microhardness suitable tests were performed in the parallel plane related to the extrusion direction with a use of the Vickers hardness tester. The tests were also carry out to determine compressive strength static compression. It has been found that the process of low-energy agitation of the input powders causes relatively uneven distribution of irregular, mostly agglomerated reinforcement particles in the matrix. The composite materials produced in the process of high-energy grinding are characterized by a different structure: the halloysite reinforcement particles are very evenly distributed, rarely forming any agglomerations. The composite materials obtained as a result of mechanical synthesis and hot extrusion are characterized by the structure of evenly distributed, disperse mineral phase particles in fine-grain matrix of EN AW-AlMg1SiCu alloy, thus facilitating the obtainment of higher values of strength properties in comparison to the initial alloy. The nanostructural composite materials reinforced with halloysite particles with 15% mass share are characterized by more than 180% higher plasticity limit and almost twice higher microhardness in comparison to the matrix material.

PL

W pracy przedstawiono wybrane wyniki badań materiałów kompozytowych o osnowie stopu aluminium wzmacnianych cząstkami haloizytowymi wytworzonych z wykorzystaniem metod metalurgii proszków: mechanicznego mielenia oraz kolejno prasowania i wyciskania na gorąco. Badane materiały kompozytowe wytworzono z proszku stopu aluminium EN AW-AlMg1SiCu, stanowiącego materiał osnowy i wzmacnianego nanorurkami haloizytowymi. Do badań przygotowano trzy zestawy próbek zawierających odpowiednio 5, 10 i 15% masowo cząstek wzmacniających, mielonych w wysokoenergetycznym młynie kulowym. Proszki kompozytowe otrzymane w procesie mechanicznego mielenia sprasowano na zimno za pomocą prasy hydraulicznej w formie o średnicy 25 mm pod ciśnieniem 300 MPa, a następnie wyciskano w temperaturze 480°C bez odgazowania, w koszulce osłonowej. Strukturę opracowanych materiałów kompozytowych zbadano za pomocą mikroskopii świetlnej, a także skaningowej i transmisyjnej mikroskopii elektronowej. Sposobem Vickersa zmierzono twardość wyciskanych materiałów kompozytowych na zgładach poprzecznych, a na uniwersalnej maszynie wytrzymałościowej wykonano badania wytrzymałości na ściskanie. W celu oceny wpływu oddziaływania procesu mechanicznego mielenia proszków wyjściowych na własności badanych materiałów kompozytowych w porównaniu z procesem mieszania tych samych proszków zastosowano dwa rodzaje procesu mielenia. Stwierdzono, że proces niskoenergetycznego mieszania proszków wyjściowych powoduje stosunkowo nierównomierne rozłożenie nieregularnych, w większości zaglomerowanych cząstek wzmocnienia w metalowej osnowie. Odmienną strukturą cechują się materiały kompozytowe wytworzone w procesie wysokoenergetycznego mielenia: haloizytowe cząstki wzmacniające są rozłożone bardzo równomiernie, rzadko tworząc skupiska. Otrzymane w procesie mechanicznej syntezy i wyciskania na gorąco materiały kompozytowe charakteryzują się strukturą równomiernie rozłożonych, rozdrobnionych cząstek fazy mineralnej w drobnoziarnistej osnowie stopu EN AW-AlMg1SiCu, sprzyjającą osiąganiu wyższych wartości własności wytrzymałościowych w porównaniu ze stopem wyjściowym. Wytworzone nanostrukturalne materiały kompozytowe wzmacniane cząstkami haloizytowymi o udziale masowym 15% charakteryzują się w porównaniu z materiałem osnowy większą o ponad 180% granicą plastyczności oraz ponad dwukrotnie większą mikrotwardością.

16

Aluminium AlMg1SiCu Matrix Composite Materials Reinforced with Halloysite Particles

Dobrzański L. A., Tomiczek B., Pawlyta M., Król M.

Archives of Metallurgy and Materials

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2014

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Vol. 59, iss. 1

335--338

EN

In this work selected results of investigations of the new AlMg1SiCu matrix composite materials reinforced with halloysite particles manufactured by powder metallurgy techniques including mechanical alloying and hot extrusion are present. The composite materials obtained as a result of mechanical synthesis and hot extrusion are characterized with the structure of evenly distributed, disperse reinforcing phase particles in fine-grain matrix of AlMg1SiCu alloy, facilitate the obtainment of higher values of strength properties, compared to the initial alloy. The nanostructural composite materials reinforced with halloysite nanotubes with 15 mass % share are characterized by almost twice as higher micro-hardness - compared to the matrix material.

PL

W pracy przedstawiono wybrane wyniki badań materiałów kompozytowych o osnowie stopu AlMg1SiCu wzmacnianych cząstkami hałoizytowymi wytworzonymi z wykorzystaniem metod metalurgii proszków, w tym mechanicznej syntezy i wyciskania na gorąco. Otrzymane w procesie mechanicznej syntezy i wyciskania na gorąco materiały kompozytowe charakteryzują się strukturą równomiernie rozłożonych, rozdrobnionych cząstek fazy wzmacniającej w drobnoziarnistej osnowie stopu AlMg1SiCu, sprzyjającą osiąganiu wyższych wartości właściwości wytrzymałościowych w porównaniu do stopu wyjściowego. Wytworzone nanostrukturalne materiały kompozytowe wzmacniane nanorurkami hałoizytowymi o udziale masowym 15% charakteryzują się - w porównaniu do materiału osnowy - ponad dwukrotnie większą mikrotwardością.

17

Effect of carbon nanotubes content on morphology and properties of AlMg1SiCu matrix composite powders

Dobrzański L., Macek M., Tomiczek B.

Archives of Materials Science and Engineering

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2014

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Vol. 69, nr 1

12--18

EN

Purpose: The main purpose of this work is to determine morphology, as well as technological and mechanical properties of aluminium matrix powder reinforced with multi-walled carbon nanotubes (MWCNTs) using powder metallurgy techniques. Dispersion of the multi-walled carbon nanotubes was achieved by using mechanical milling in a high energy ball mill. The addition of MWCNTs cause significant improvement in mechanical properties of Al/MWCNTs nanocomposites what is confirmed with more than a threefold increase in the hardness of composite powders, as compared to this value before milling. Design/methodology/approach: The main problem of the study is the agglomeration and poor distribution of carbon nanotubes in the matrix material. In order to achieve uniform dispersion of carbon nanotubes in aluminium alloy matrix mechanical milling was used. Additional problem is possible formation of the brittle aluminium carbides in the result of reaction between carbon nanotubes and aluminium particles. Findings: On the basis of micro-hardness testing has found that a small addition of carbon nanotubes in an amount of 0.5% by volume increases composites hardness by 13%, while the addition of carbon nanotubes in an amount of 5% by volume results in an increase of 37%.Practical implications: Composite powders carbon nanotubes were prepared using powder metallurgy method which shows the practical implications in manufacturing of nanocomposites. Originality/value: The investigation results shows that the technology of composite materials manufacturing can find the practical application in the production of new light metal matrix composites. It was found that carbon nanotubes, used as reinforcing phase, have influence on the properties of metal matrix composites.

18

Composite materials based on AlMg1SiCu aluminium alloy reinforced with halloysite particles

Tomiczek B., Dobrzański L.A.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 61, nr 1

39--46

EN

Purpose: The present work describes microstructure and technological, as well as mechanical properties of AlMg1SiCu matrix composite materials reinforced with halloysite particles by powder metallurgy techniques and hot extrusion. Design/methodology/approach: Mechanical milling, compacting and hot extrusion successively are considering as a method for manufacturing metal composite powders with a controlled fine microstructure and enhanced mechanical properties. Findings: A structure of newly developed composite materials reinforced with halloysite nanotubes prove that a mechanical milling process allow to improve the arrangement of reinforcing particles in the matrix material. A homogenous structure with uniformly arranged reinforcing particles can be achieved by employing reinforcement with halloysite nanotubes if short time of milling is maintained thus eliminating an issue of their agglomeration. Strong plastic deformations and fine grain size and the dispersion of halloysite reinforcing particles caused by mechanical milling is substantially reinforcing the composite materials reinforced with halloysite nanotubes as expressed with nearly a threefold increase in the hardness of composite powders as compared to the value of this quantity before milling. Research limitations/implications: Contributes to knowledge about technology, structure and properties of aluminium alloy matrix composite material reinforced with mineral nanoparticles. Practical implications: As the fraction of halloysite nanotubes is growing to 15%, structural changes in the powders of composite materials subjected to mechanical milling are reaching the set condition 3 times faster as compared to the matrix material. Originality/value: It has been confirmed that halloysite nanotubes can be applied as an effective reinforcement in the aluminium matrix composites. Deformation, grain size reduction and dispersion conduce to strengthening of the composite powders.

19

Mechanically milled aluminium matrix composites reinforced with halloysite nanotubes

Dobrzański L.A., Tomiczek B., Adamiak M., Gołombek K.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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Vol. 55, nr 2

654--660

EN

Purpose: The present work describes fabrication of aluminium AlMg1SiCu matrix composite materials reinforced with halloysite nanotubes by powder metallurgy techniques and hot extrusion. Design/methodology/approach: Mechanical milling, compacting and hot extrusion successively are considering as a method for manufacturing metal composite powders with a controlled fine microstructure and enhanced mechanical properties. It is possible by the repeated welding and fracturing of powders particles mixture in a highly energetic ball mill. Findings: The milling process has a huge influence on the properties of powder materials, changing the spherical morphology of as-received powder during milling process to flattened one due to particle deformation followed by welding and fracturing particles of deformed and hardened enough which allows to receive equiaxial particles morphology again. The investigation shows that so called brittle mineral particles yields to plastic deformation as good as ductile aluminium alloy particles. That indicates that the halloysite powder can play a role of the accelerator during mechanical milling. High energy ball milling as a method of mechanical milling improves the distribution of the halloysite reinforcing particles throughout the aluminium matrix, simultaneously reducing the size of particles. The apparent density changes versus milling time can be used to control the composite powders production by mechanical milling and the presence of halloysite reinforcements particles accelerates the mechanical milling process. Research limitations/implications: Contributes to knowledge about technology, structure and properties of aluminium alloy matrix composite material reinforced with mineral nanoparticles. Practical implications: Conducted research shows that applied technology allows obtaining very good microstructural characteristics. Originality/value: It has been confirmed that halloysite nanotubes can be applied as an effective reinforcement in the aluminium matrix composites. Deformation, grain size reduction and dispersion conduce to hardening of the composite powders. Mechanical milling cause a high degree of deformation, decrease the grain size even to nanoscale and create an enormously uniform distribution of reinforcing phases or oxides in the structure of the metal.

20

Surface morphology of thin films polyoxadiazoles

Weszka J., Szindler M.M., Chwastek-Ogierman M., Bruma M., Jarka P., Tomiczek B.

Journal of Achievements in Materials and Manufacturing Engineering

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2011

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Vol. 49, nr 2

224--232

EN

Purpose: The purpose of this paper was to analyse the surface morphology of thin films polyoxadiazoles. Design/methodology/approach: SSix different polymers which belong to the group of polyoxadiazoles were dissolved in the solvent NMP. Each of these polymer was deposited on a glass substrate and a spin coating method was applied with a spin speed of 1000, 2000 and 3000 rev/min. Changes in surface topography and roughness were observed. An atomic force microscope AFM Park System has been used. Photos have been taken in noncontact mode while observing an area of 10 x 10 microns. Findings: The analysis of images has confirmed that the quality of thin films depends upon the used polymers. It was also observed that the parameters of the spin coating method have significant effect on the morphology and the surface roughness. The speed of the spin has got a strong impact on the topography of the thin films obtained. Research limitations/implications: The morphology of polyoxadiazoles thin films has been described. This paper include description how the spin speed influences the morphology of polymer thin films. In order to use a polymer thin film in photovoltaics or optoelectronics it must have a uniform thickness and a low surface roughness. Further research, in which the optical properties of thin films are investigated, is strongly recommended. Practical implications: Conductive polymers may find applications in photovoltaics or optoelectronics. It is important to study this group of material engineering and to find a new use for them. Materials from which thin films are made of will have an impact on the properties and characteristics of electronics devices in which they are be applied. Originality/value: The value of this paper is defining the optimal parameters of spin-coating technology for six polyoxadiazoles. The results allow the choosing optimal parameters of the deposition process. Spin coating is a very good method to obtain thin films which are obligated to heve the same thickness over the whole surface.