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Enhanced Microwave Absorption of CNT Composites Mixing with Fe3O4 and Carbonyl Iron

Park J. H., Choi J., Lee K., Park J., Song J. K., Jeon E.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 3

1513--1516

EN

We fabricated two different kinds of composite materials for absorbing microwave in a frequency range of 2 to 18 GHz using coaxial airline and thru-reflect-line (TRL) method. The composite materials having carbon nanotube (CNT) with carbonyl iron (CI) or iron oxide (Fe3 O4 ) were fabricated by mixing each components. Magnetic properties were measured by SQUID equipment. Complex permittivity and complex permeability were also obtained by measuring S-parameters of the toroidal specimen dispersing CI/CNT and Fe3 O4 /CNT into the 50 weight percent (wt%) epoxy resin. The real permittivity was improved by mixing the CNT however, the real permeability was same as pure magnetic powders. The CI/CNT had a maximum value of real permittivity and real permeability, 11 and 1.4 at 10 GHz, respectively. The CNT composites can be adapted to the radar absorbing materials, band width 8-12 GHz.

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The dependence of the functional properties of the nanocomposite with matrix made of Epidian 100 resin due to size of reinforcement made of Fe67Co10Ni1W2B20 alloy

Siejka A., Szota M., Nabiałek M., Pietrusiewicz P., Łukaszewicz A., Klimas J., Błoch K.

Journal of Achievements in Materials and Manufacturing Engineering

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2016

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Vol. 77, nr 2

64--68

EN

Purpose: Objective of the paper was to determine the effect of particle size fraction for the mechanical properties of powders and magnetic fields produced powder consisting of ironbased alloys and an epoxy resin (trade name Epidian 100) which was obtained as a result of press. Design/methodology/approach: Samples were produced by the method of singleunilateral pressing. To achieve the pursued objective, the following tests were performed: microstructural observations – light microscope, roughness tests, statistical the hysteresis loops. Findings: On the basis of the research it can be stated that with the increase in the size fraction of the reinforcement of composites increased their roughness and greater was their density. In addition, with the increase in the size fraction of the reinforcement of composites increased the field coercivity, while decreasing saturation magnetisation. Research limitations/implications: The study not specified time and the influence of baling pressure on the mechanical properties and magnetic properties of composites produced using the single-uniaxial press. Practical implications: The division into three fractions powder using a sieve analysis did not allow for adequate separation of powders. In each fraction were small particles. In the future, it will be used a long period of time sieving powders. Originality/value: The paper presents new method producing magnetic composites, where possible was give shape by using epoxy resin.

3

The impact of the powder fraction on the structural and magnetic properties of polymer matrix composites

Bukowska A., Szota M., Nabiałek M., Błoch K., Łukaszewicz A., Klimas J.

Archives of Materials Science and Engineering

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2014

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Vol. 68, nr 2

59--65

EN

Purpose: The preparation of composite materials composed of Fe66Co10Ni2W2B20 alloy powders and epoxy resin and determining the influence of the alloy powders fraction Fe66Co10Ni2W2B20 on mechanical and magnetic properties of produced materials. Design/methodology/approach: Tested samples made of Fe66Co10Ni2W2B20 alloy powders and epoxy resin, were produced by pressing with pressure 5MPa during 10 s. In order to examine produced materials structural studies were conducted (observation under an optical microscope, a scanning electron microscope with EDS analysis), mechanical (measurement of surface roughness) and magnetic (obtaining static magnetic hysteresis loop based on measurements were made using a vibrating magnetometer (VSM)).Results: Pressing of Fe66Co10Ni2W2B20 alloy powders and epoxy resin allows to obtain composite materials, which are divided into three fractions, namely: 20-50 μm 50-100 μm 100-200 μm characterized, with the increasing size of the fraction of reinforcement, the better development of the area. Magnetic studies show that with increasing size of the fraction of the reinforcement, those materials have smaller coercive field, as well as the observed decrease in saturation magnetization. Originality/value: By combining Fe66Co10Ni2W2B20 alloy powders and epoxy resin composite materials with different fractions of reinforcement, which exhibit better properties than the starting materials used to receive are possible to obtain.

4

Wpływ zawartości proszku Nd-Fe-B na właściwości magnetyczne dielektromagnesów wtryskiwanych

Paszkowski L., Ślusarek B., Biało D.

Rudy i Metale Nieżelazne

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2005

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R. 50, nr 3

140-143

PL

Omówiono proces formowania wtryskowego dielektromagnesów złożonych z proszku magnetycznego Nd-Fe-B i polistyrenowej osłony. Zastosowano proszek o kulistym i płatkowym kształcie cząstek w ilości 30, 40, 50 i 60 % obj. Wykazano, że zasadniczy wpływ na parametry magnetyczne dielektromagnesów Bgamma H,CB, (BH)max wywiera ilość proszku we wtryskiwanym materiale. Przy określonej ilości proszku wyższe wartości właściwości magnetycznych uzyskano dla proszku o płatkowych cząstkach.

EN

Injection molding process of dielectromagnets consist of Nd-Fe-B magnetic powder and polystyrene matrix was described. Magnetic powder having spherical and flaky shape particle with volume fraction of 30, 40, 50 and 60 % was used. It was shown that volume fraction of the powder in the injected material strongly influence on magnetic parameters of dielectromagnets Bgamma H,CB and (BH)max . At defined fraction of powder higher value of magnetic properties was obtained for the flaky shape powder particles.