Wyniki wyszukiwania - BazTech

1

Wstępne badania nad oceną parametrów mechanicznych ochronnych materiałów tekstylnych powlekanych pastą poliuretanową z dodatkiem grafitu i nanorurek węglowych

Irzmańska Emilia, Boczkowska Anna, Żyłka Emilia, Jurczyk-Kowalska Magdalena, Strycharz Kamila, Szroeder Paweł

Przemysł Chemiczny

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2024

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T. 103, nr 1

117--123

PL

Omówiono wpływ grafitu oraz nanorurek węglowych dodanych do pasty powlekającej materiał tekstylny na podstawowe parametry mechaniczne. Przedstawiono wyniki badań odporności na przecięcie metodą TDM i coup test oraz odporności na ścieranie dla otrzymanych powlekanych materiałów tekstylnych.

EN

Meta-aramid fibers were coated with polyurethane paste mixed with graphite and C nanotubes in various configurations. Cutting and abrasion resistance as well as SEM anal. of composites were performed. The effect of the applied coating on the mech. parameters was examined.

2

Wpływ zawartości grafitu na właściwości mechaniczne warstw hybrydowych Ni-P/Si3N4/grafit osadzonych na stopie AW-7075 metodą redukcji chemicznej

Czapczyk Kazimierz

Przemysł Chemiczny

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2024

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T. 103, nr 1

86--92

PL

Przedstawiono wpływ obecności grafitu jako fazy dyspersyjnej na właściwości mechaniczne warstw hybrydowych Ni-P/Si₃N₄/grafit, które osadzono metodą redukcji chemicznej na stopie glinu AW-7075. Wykonano badania morfologii powierzchni warstw metodą mikroskopii świetlnej i skaningowej. Dalszą część pracy stanowiły badania mechaniczne, czyli pomiary mikrotwardości warstw oraz ich adhezji do aluminiowego podłoża, a także analizy wpływu obecności grafitu na podstawowe właściwości materiału powłokowego. Zbadano próbki ze stopu AW-7075, na których osadzono metodą bezprądową powłoki hybrydowe i porównawczo nanokompozytowe o różnym składzie chemicznym, modyfikowanym zawartością faz dyspersyjnych.

EN

The mech. and adhesive properties of Ni-P/Si₃N₄ and Ni-P/Si₃N₄/graphite coatings deposited using the electroless method on the AW-7075 Al alloy were compared. Coatings with different chem. compns., modified by the content of dispersion phases (Si₃N₄ and graphite), were used. Microhardness and adhesion of the layers to the Al substrate were measured. The impact of the presence of graphite on the basic properties of the coating material was analyzed. The surface morphol. of the layers was examined using light microscopy and SEM. The incorporation of Si₃N₄ and graphite into the coating material resulted in a several-fold increase in the microhardness of the surface layer compared to the Al alloy.

3

Study on Electromagnetic Properties of Graphite/Graphene/Silver-Coated Copper Powder Monolayer Coated Composites

Liu Yuanjun, Han Xiaohui, Bao Wenli, Ding Xiongwei, Zhao Xiaoming

Fibres & Textiles in Eastern Europe

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2023

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Vol. 31, no. 1

83--90

EN

With the rapid development of electronic technology and military techniques, electromagnetic protection materials are becoming more and more significant to people. Harmful electromagnetic radiation not only affects the normal operation of electronic equipments and military security, but also has a serious impact on human health. At present, using absorbing and shielding materials are effective means to reduce the harm of electromagnetic waves. In this project, graphite, graphene and silver-coated copper powder coated composites were prepared using PU-2540 polyurethane and adopting a coating process for the substrate on plain polyester/cotton fabric. The controlled variable method was used to prepare and study the electromagnetic properties of single-layer coating composites with different functional particle contents. The result showed that within the frequency range of 0.01GHz~1.0GHz, when the total mass of functional particles was 48% relative to that of the polyurethane, the value of the real part of the dielectric constant of the sample remained the largest and its polarization ability was the strongest. Within the frequency range of 0.08GHz~1.0GHz, when the content of functional particles was 24% relative to that of the polyurethane, the value of the imaginary part of the dielectric constant and the loss of the tangent value of the sample kept the maximum, and the loss and attenuation ability with respect to electromagnetic waves were both the strongest. Within the frequency range of 1.3GHz~2.0GHz, when the content of functional particles was 36% relative to that of the polyurethane, the value of the reflection loss of the sample was -26.93dB, and the minimum value of the reflection loss was obtained at a frequency of 1.6GHz, at the moment of which, the absorbing property of the sample was the best.

4

The Formation, Properties and Use of Dispersed Iron-Graphite Metallurgical Waste

Dan Leonid, Maslov Vladimir, Trofimova Larysa, Cios Grzegorz

Journal of Casting & Materials Engineering

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2022

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Vol. 6, no. 4

81--92

EN

Dispersed wastes containing graphite, iron, and its oxides, getting into the air and accumulating in landfills, cause serious harm to human health and the environment. Moreover, even if the issue of the localization of these wastes has been solved successfully, their disposal has not yet been fully organized. In the present study, a systematic analysis of the dispersed iron-graphite waste (IGW) conditions for the formation at metallurgical enterprises, their structure, and their properties were carried out. In this case, special attention is focused on the electrophysical properties: specific saturation magnetization and volume resistivity. The presence of magnetic properties in IGW, combined with low electrical resistivity, makes IGW a promising and inexpensive raw material for obtaining cheap composite materials with radio shielding and radio absorbing properties in the microwave range. As a result of the research, effective ways of improving the magnetic properties of IGW by high-temperature treatment were obtained. The practical result of the research was the development and implementation of a technological scheme of dispersed IGW complex processing, which makes it possible to solve a twofold task – to exclude the ingress of iron-graphite wastes into the environment and to obtain a cheap material for protection against microwave radiation.

5

A study on mechanical and wear behaviour of graphite filled sisal-glass-epoxy hybrid composites

Suresh Kumar Devendrappa, Sanjeevamurthy, Mallesh Goud, Pavankumar Ravikumar, Vasanth Kumar Hasthinapura Seena Naik

Composites Theory and Practice

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2022

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R. 22, nr 2

106--113

EN

In recent years, advancements in development of composite materials can be distinctively observed and taking ecological factors into account, researchers are currently working on the development of natural fibre composites for various applications. The current work concentrates on assessment of the mechanical and wear characteristics of sisal-glass (natural and synthetic) epoxy hybrid graphite filled composites. A comparative characteristic study was performed in the study between synthetic (glass) and natural (sisal) FRP composites and it was found that graphite filled FRP composites exhibit excellent tensile properties, flexural modulus enhanced by 35.2%, the hardness and impact strength were improved with the addition of graphite filler. Statistical analysis was conducted using the design of experiments with the help of ANOVA software. From the tribology tests, it was noticed that the COF and wear loss of the composites with the natural reinforcement are comparatively higher than that of the synthetic fibre. It is evident from ANOVA and regression analysis that the reinforcement has 57.99% influence on the wear rate. Due to increased environmental consequences, natural FRP composites are recommended to be used in as automotive brake friction material and aerospace body parts.

6

Evaluation of Wear Mechanisms of Graphites Used for Crystallisers for Continuous Casting

Brudny Anna, Kulasa Joanna, Juszczyk Barbara, Myalski Jerzy, Roskosz Stanisław, Wycisk R., Kwaśniewski Paweł, Strzępek Paweł, Poręba Marek

Archives of Foundry Engineering

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2022

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Vol. 22, iss. 4

109--115

EN

This paper presents the results of research concerning the evaluation of tribological properties of graphite materials used, among others, for crystallisers for continuous casting of non-ferrous metals and their alloys. Graphite materials differing not only in their physical properties but also in the technology of their production were selected from a wide range of commercially available products. Wear resistance investigations of the tested graphite materials were carried out on a pin-on-disc tribometer under technically dry friction conditions on a sliding distance of 1000 m. A constant load but variable speed was used in the tests. The mean value of the coefficient of friction and the wear of the material were determined based on the tribological tests carried out. It was observed that as the speed increases, the average value of the coefficient of friction decreases, while the wear increases. A microstructural analysis of the wear track showed that the friction mechanism depends mainly on the graphite formation technology, which is related to the microstructure of the tested materials, and to a lesser extent to their physical and mechanical properties. Varying the speed values made it possible to trace changes in the wear mechanism, on the basis of which it is possible to predict the durability and reliability of graphite crystalliser operation.

7

Influence of extruder plasticizing systems on the selected properties of pla/graphite composite

Kaczor Daniel, Bajer Krzysztof, Domek Grzegorz, Madajski Piotr, Raszkowska-Kaczor Aneta, Szroeder Paweł

Acta Mechanica et Automatica

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2022

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Vol. 16, no. 4

316--324

EN

Twin-screw extrusion is a crucial method for the direct inserting of carbon micro- and nanomaterials into a polymer matrix using a dry procedure. The study aimed to determine the influence of the parameters of the twin-screw extruder plasticizing system on the dispersion homogeneity and distribution of graphite filler in the polylactide polymer matrix and overall quality of the composite. As a filler, a graphite micropowder with a 5 μm lateral size of platelets was used at concentration of 1 wt.%. Three configurations of screws with different mixing intensity and various types segments were considered in the extrusion experiments. Morphology and chemical structure of the obtained composites were examined using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy – attenuated total reflectance (FTIR-ATR) and Raman spectroscopy. Differential scanning calorimetry (DSC) and melting flow rate measurements (MFR) were used to asses thermal and rheological properties of the composites. Samples of the polylactide/graphite composites were also subjected to mechanical tests. The results show that the selection of the mechanical parameters of twin-screw extruder plasticizing system plays a key role in the preparation of the homogeneous PLA/graphite composites. Incorrect selection of the screw geometry results in poor mixing quality and a significant deterioration of the mechanical and thermal properties of the composites. Optimised mixing and extrusion parameters can be the starting point for the design of efficient twin-screw extruder plasticizing system for fabrication of PLA composites with carbon nanotube and graphene fillers.

8

Influence of laser texturing on tribological properties of DLC coatings

Radek Norbert, Tokar Dorota, Kalinowski Artur, Pietraszek Jacek

Production Engineering Archives

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2021

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Vol. 27, Iss. 2

119--123

EN

The work presents the use of laser texturing of DLC coatings to improve tribological properties. The coatings were applied by the PVD method to the rings made of 4H13 steel. The surface texturing was = 343 nm.performed with the TruMICRO 5325c picosecond laser with the radiation wavelength The surface microstructure analysis, surface microgeometry and microhardness measurements and tribological tests were carried out. The problem presented in the paper can be used to extend the knowledge of the areas of application of DLC coatings, especially in sliding friction pairs.

9

High-temperature carbothermal dephosphorization of Malaysian monazite

Udayakumar Sanjith, Sheikh Abdul Hamid Sheikh Abdul Rezan, Baharun Norlia, Pownceby Mark

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 6

140--155

EN

High-temperature carbothermal reduction experiments with graphite powder were conducted to assess the dephosphorization behavior of Malaysian monazite concentrate. Thermodynamic analysis of the possible dephosphorization reactions was conducted to evaluate the feasibility of the carbothermal reduction of the monazite phases. The effects of temperature, particle size, and monazite to carbon ratio were then investigated under different conditions. The carbothermal reduction experiments were conducted based on the Taguchi design method, and up to 97% of phosphorous removal was achieved under optimized conditions. The optimal conditions for dephosphorization were determined as; a reduction temperature of 1350 °C, a particle size of -75 μm, and monazite to carbon molar ratio of 0.3. Microstructural and phase characterization of the dephosphorized products revealed that CeO2, Nd2O3, La2O3, and Pr2O3 oxide phases were prominent, and no residual peaks of monazite remained in the reduced products. The information gained from the study can aid in the design of a suitable post-dephosphorization hydrometallurgical treatment for exploiting Malaysian monazite as a local source of REEs.

10

Study of the Dielectric Properties and Conductivity of Double Coated Glass Fibre Felt Composites

Liu Yuanjun, Wang Caixia, Ma Yiping, Liu Yanyan, Wu Haiying, Zhao Xiaoming

Fibres & Textiles in Eastern Europe

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2021

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Vol. 29, no. 4 (148)

75--80

EN

Graphite/talcum powder double-coated glass fibre felt composites were prepared using glass fibre felt as the base material, graphite as the surface absorbing agent, talcum powder as the underlying absorbing agent, epoxy resin E44 as the adhesive and low molecular 650 polyamide as the curing agent. The influences of the surface graphite content and underlying talcum powder content on the dielectric properties and conductivity of glass fibre felt composites were the main focus of the investigation. Results showed that when the frequency is less than 103 Hz, the values of the real and imaginary parts of the dielectric constant for double-coated glass fibre felt composites are largest when the surface graphite content is 50%. When the frequency is larger than 106 Hz, the value of the real part of the conductivity is largest when the graphite contents are 40% and 50%. When the frequency is less than 104Hz, the real part of the dielectric constant of the glass fiber mat composites is the largest when the talc content is 40%, and when talc content is 60%, the imaginary part of dielectric constant of glass fiber mat composites is the largest. The maximum loss tangent value for the composites occurs when the talcum powder content is 40%. When the frequency is larger, the value of the real part of the conductivity increases gradually.

PL

W pracy przygotowano podwójnie powlekane kompozyty filcu z włókna szklanego w postaci grafit/talk. Użyto filcu z włókna szklanego jako materiału bazowego, grafitu jako powierzchniowego środka pochłaniającego, talku jako podstawowego środka pochłaniającego, żywicy epoksydowej E44 jako kleju i poliamidu 650 o niskiej masie cząsteczkowej jako środek utwardzającego. Głównym przedmiotem badań było określenie wpływu zawartości grafitu powierzchniowego oraz zawartości proszku talku na właściwości dielektryczne i przewodność kompozytów z filcu z włókna szklanego. Wyniki wykazały, że gdy częstotliwość jest mniejsza niż 103 Hz, wartości części rzeczywistej i urojonej stałej dielektrycznej dla podwójnie powlekanych kompozytów z filcu z włókna szklanego są największe, gdy zawartość grafitu powierzchniowego wynosi 50%. Gdy częstotliwość jest większa niż 106 Hz, wartość rzeczywistej części przewodnictwa jest największa, gdy zawartość grafitu wynosi 40% i 50%. Maksymalna wartość tangensa strat dla kompozytów występuje, gdy zawartość talku wynosi 40%. Gdy częstotliwość jest większa, wartość rzeczywistej części przewodnictwa stopniowo wzrasta.

11

Graphite-glass screen-printed film electron emitters

Matusiak Tomasz, Laszczyk Karolina

Przegląd Elektrotechniczny

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2020

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R. 96, nr 5

75--78

EN

In this paper, we present the technology and principle performance of film electron emitters made of graphite-glass composite paste using screen printing. As a result, we got working emitters with emission current densities and the turn-on electric field voltage comparable to film electron emitters made of nano-scale carbon composites that were reported in the literature.

PL

W tym artykule prezentujemy technologię i podstawowe charakterystyki pracy warstw emitujących elektrony i wykonanych techniką sitodruku z wykorzystaniem pasty kompozytowej grafitowo-szkłanej. Emitery te osiągnęły gęstości prądów emisji oraz napięcie progowe, przy którym rozpoczyna się emisja, porównywalne do tych, jakie zostały opisane w literaturze naukowej dla materiałów węglowych w nano-skali.

12

Modeling electromagnetic nanostructures and experimenting with nanoelectric elements to form periodic structures

Steinbauer Miloslav, Pernica Roman, Zukal Jiri, Kadlec Radim, Bachorec Tibor, Fiala Pavel

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2020

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T. 10, nr 4

4--14

EN

We discuss the numerical modeling of electromagnetic, carbon-based periodic structures, including graphene, graphane, graphite, and graphyne. The materials are suitable for sub-micron sensors, electric lines, and other applications, such as those within biomedicine,photonics, nano-and optoelectronics; in addition to these domains and branches, the applicability extends into, for example, microscopic solutions for modern SMART elements. The proposed classic and hybrid numerical models are based on analyzing a periodic structure with a high repeatability, and they exploitthe concept of a carbon structure having its fundamental dimension in nanometers. The models can simulate harmonic and transient processes;are capable of evaluating the actual random motion of an electric charge as a source of spurious signals; and consider the parameters of harmonic signal propagation along the structure. The results obtained from the analysis are utilizable for the design of sensing devices based on carbon periodic structures andwere employed in experiments with a plasma generator.The aim is to provide a broader overview of specialized nanostructural modeling, or, more concretely, to outline a model utilizable in evaluating the propagation of a signal along a structure’s surface.

PL

W artykule omówiony został procesnumerycznegomodelowaniaelektromagnetycznych, węglowych struktur okresowych, w tym grafenu, grafanu, grafitu i grafinu. Materiały te nadają się do czujników submikronowych, przewodów elektrycznych i innych zastosowań, takich jak biomedycyna, fotonika, nano-i optoelektronika.Oprócz tych dziedzin i gałęzi przemysłu, zastosowanie materiałów pokrywa się także na przykład z mikroskopijnymirozwiązaniamidla nowoczesnych elementów SMART. Proponowane klasyczne i hybrydowe modele numeryczneopierają się na analizie okresowej struktury o wysokiej powtarzalności i wykorzystują koncepcję struktury węglowej o podstawowym wymiarze w nanometrach. Modele mogą symulować procesy harmoniczne i przejściowe,potrafią ocenić rzeczywisty losowy ruch ładunku elektrycznego jako źródła fałszywych sygnałówi uwzględniająparametry propagacji sygnału harmonicznego wzdłuż konstrukcji. Rezultaty uzyskane w wyniku analizy można wykorzystać do projektowania czujników opartych na węglowych strukturach okresowych oraz do eksperymentów z generatorem plazmy. Celem jest zapewnienie szerszego przeglądu specjalistycznego modelowania nanostrukturalnego lub, bardziej konkretnie, zarysumodelu nadającego się do oceny propagacji sygnału wzdłuż powierzchnistruktury.

13

Fly ash/phenolic resin composite for brake pad application : fabrication, materials and thermal properties

Savetlana Shirley, Lubis Asnawi, Aditya Lingga, Irfan Muhammad, Siadari Dedi, Efendi Gunawan, Yusuf Muhammad, Jefri Hel

Composites Theory and Practice

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2020

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R. 20, nr 3-4

95--101

EN

Nowadays, many parts of automotive components are made of composites. One application of composites is brake lining material in braking systems. Fly ash is waste from burning coal in the power plant industry. Fly ash was added to a polimer matrix to enhance the wear properties of the composite. The appropriate temperature and pressure for composite fabrication were chosen from the composite which has the highest hardness. The addition of 30 wt.% fly ash to the phenolic resin matrix resulted in the lowest specific abrasion of the composite. Additions of graphite, iron powder and nitrile butadiene rubber increased the specific abrasion of the fly ash/phenolic resin composite. Scanning electron microscope micrographs showed the distribution and agglomeration of the particles in the phenolic resin matrix. The addition of fly ash to the phenolic resin matrix also increased the temperature resistance of the composite. Thermogravimetric analysis shows that the starting temperatures for decomposition of the composite constituents shifted to higher temperatures as the fly ash content increases.

14

The Influence of Temperature on the Rheological Properties of Fibrous Lubricating Compounds with Selected Solid Additives

Paszkowski Maciej, Szott Michał

Tribologia

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2019

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nr 5

71--76

EN

The study evaluated the effect of temperature on the values of yield stress and cohesion energy of lubricating compounds thickened with calcium 12-hydroxystearate, prepared on the basis of mineral oil. Lubricating compounds without additives and with selected solid additives in the form of copper particles, graphite, molybdenum disulphide, and polytetrafluoroethylene were analysed. A rotational rheometer working with a plate-plate geometry was used for rheological studies. The influence of temperature on the rheological properties of lubricating compounds with additives was observed. Solid additives caused significant changes in the structure of the soap thickener, especially at negative temperatures.

PL

W pracy oceniono wpływ temperatury na wartości naprężenia stycznego granicznego i energii kohezji kompozycji smarowych zagęszczanych 12-hydroksystearynianem wapnia, wytworzonych na bazie oleju mineralnego. Analizie poddano kompozycje smarowe bez dodatków oraz z wybranymi dodatkami stałymi w postaci cząstek miedzi, grafitu, dwusiarczku molibdenu oraz politetrafluoroetylenu. Wyniki badań wskazały istotny wpływ temperatury i dodatków na właściwości reologiczne kompozycji smarowych.

15

Critical Raw Materials – What´s the Crux of the Matter?

Dvoracek Jaroslav, Sousedikova Radmila, Jurekova Zdenka, Matyasova Zuzana

Inżynieria Mineralna

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2019

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R. 21, nr 1/2

97--99

EN

The paper takes into account mineral commodities that have been listed as critical by the EU Commission. It concentrates attention on the issue of global demand/supply balances, and summarizes causes for critical listing of these commodities.

PL

W artykule przedstawiono surowce mineralne wymienione przez Komisję Europejską jako krytyczne. Koncentruje uwagę na globalnym popycie i podsumowuje przyczyny zestawienia listy pierwiastków krytycznych.

16

The influence of the addition of graphite on the tribological properties of polylactic (PLA) applied in 3D printing technology

Pawlak W., Wieleba W., Kluczyński J., Śnieżek L.

Tribologia

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2018

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nr 1

89--93

EN

W niniejszej pracy przedstawiono wyniki badań wpływu dodatku grafitu do PLA na zużycie liniowe oraz współczynnik tarcia. Jako próbkę zastosowano walec o średnicy 8 milimetrów wytworzony w procesie Fused Filament Fabrication, popularnie zwanym drukiem 3D. Badania zostały przeprowadzone na stanowisku typu pin-on-disc, w którym wykorzystano wyżej wspomnianą próbkę, współpracującą ślizgowo ze stalową tarczą – przeciwpróbką. Próbki użyte w badaniu wzbogacone były kolejno o 5%, 10%, 20% oraz 30% grafitu względem filamentu bazowego, tzw. Natural PLA, niewzbogaconego żadnymi dodatkami polepszającymi właściwości tribologiczne. Przeprowadzony eksperyment ma charakter badań wstępnych, a uzyskane wyniki stanowią podstawę do opracowania optymalnego składu filamentu o polepszonych właściwościach tribologicznych.

17

Konstrukcyjne kompozyty polimerowe z napełniaczami węglowymi

Polok-Rubiniec M., Włodarczyk-Fligier A., Chmielnicki B., Jurczyk S.

Przetwórstwo Tworzyw

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2018

|

T. 24, Nr 5 (185)

5--14

PL

W artykule przedstawiono charakterystykę kompozytów polimerowych z napełniaczami węglowymi. Materiały te są coraz częściej stosowane jako materiały konstrukcyjne, ze względu na swoje ciekawe właściwości, mogą stanowić konkurencję, w niektórych przypadkach nawet dla stali węglowych. W niniejszej pracy skupiono się na charakterystyce stosowanych napełniaczy węglowych: włókna węglowe i nanorurki węglowe, sadza, grafit, grafen, czysty węgiel kamienny i jego odmiany. Przedstawiono ich wpływ na właściwości różnych osnów polimerowych w zależności od zawartości napełniacza oraz możliwości aplikacyjne powstałych kompozytów.

EN

The paper presents the polymer composites with carbon fillers characterization. These materials are more and more often used as construction materials, because of their interesting properties, they can competitive, in some cases even with carbon steels. This paper focuses on the characterization of: carbon fibers, carbon nanotubes, carbon black, graphite, graphene, fine coal and it's varieties as carbon fillers phase. Their influence on the properties of various polymer matrices, depends on the filler content and application possibilities of the obtained composites were presented.

18

Influence of load and reinforcement content on selected tribological properties of Al/SiC/Gr hybrid composites

Veličković S., Miladinović S., Stojanović B., Nikolić R. R., Hadzima B., Arsić D.

Production Engineering Archives

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2018

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Vol. 18

18--23

EN

Hybrid materials with the metal matrix are important engineering materials due to their outstanding mechanical and tribological properties. Here are presented selected tribological properties of the hybrid composites with the matrix made of aluminum alloy and reinforced by the silicon carbide and graphite particles. The tribological characteristics of such materials are superior to characteristics of the matrix – the aluminum alloy, as well as to characteristics of the classical metal-matrix composites with a single reinforcing material. Those characteristics depend on the volume fractions of the reinforcing components, sizes of the reinforcing particles, as well as on the fabrication process of the hybrid composites. The considered tribological characteristics are the friction coefficient and the wear rate as functions of the load levels and the volume fractions of the graphite and the SiC particles. The wear rate increases with increase of the load and the Gr particles content and with reduction of the SiC particles content. The friction coefficient increases with the load, as well as with the SiC particles content increase.

19

Mechanisms for the improved flotation of inherently hydrophobic graphite in electrolyte solution

Lai Q., Liao Y., Liu Z., He Y., Zhao Y.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 3

944--954

EN

It is well documented that unavoidable ions in a pulp such as Mg2+, Ca2+, and K+ have a significant effect on the interaction for particles, especially for flotation of metallic sulfide minerals and clay minerals. In this study, the effect of electrolytes on the flotation of inherently hydrophobic mineral-graphite was studied. It was found that the zeta potential showed a dramatic decrease, and the reagent adsorption capacity of mineral enhanced in the present of electrolytes. The possible mechanism responsible for improved recovery was investigated by electrokinetic, surface tension and ions adsorption tests. It is likely that the hydrophobic force is stronger than the electrostatic force due to the reduced potential of graphite. This might be in favor of the formation of hydrophobic oil film leading to an increase in the graphite floatability. The experiments provided a new spectacle to study inherently hydrophobic mineral processing with electrolyte solution.

20

Comparison of mechanical flotation cell and cyclonic microbubble flotation column in terms of separation performance for fine graphite

Bu X., Zhang T., Chen Y., Peng Y., Xie G., Wu E.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 3

732--740

EN

Comparison of flotation performance between the flotation column and mechanical flotation was carried out to promote the grade and economic value of the graphite ore (15.40% ash content). The ash content of the concentrate of the mechanical flotation was 10.77% at the yield of 79.34%. In contrast, the yield of the concentrate of the column flotation was increased to 88.93% with 10.55% ash content. Comparative study of the Fuerstenau upgrading curves indicated that the column flotation was more efficient for cleaning the graphite ore in the presence of the centrifugal force field, nanobubbles (generated by hydrodynamic cavitation), and the thicker froth layer in comparison with the mechanical flotation.