Wyniki wyszukiwania - Biblioteka Nauki

1

Manufacturing of hard magnetic composite materials Nd-Fe-B

100%

Drak M. , Ziębowicz B. , Dobrzański L. A.

|

2008

|

tom Vol. 31, nr 1

91-96

EN

Purpose: This paper presents the material and technological solution which makes it possible obtaining of hard magnetic composite materials: nanocrystalline material-polymer. Design/methodology/approach: For fabrication of composite materials the Nd-Fe-B powder obtained by melt quenching technique was used and for matrix: epoxy resin (EP) or high density polyethylene (HDPE) (2.5 % wt.). Composite materials were compacted by the one-sided uniaxial pressing. The complex relationships among the manufacturing technology of these materials, their microstructure, as well as their properties were evaluated. Materialographic examination of powders morphology and the structure of composite materials were made. Findings: Composite materials show regular distribution of magnetic powder in polymer matrix. Examination of mechanical properties show that these materials have satisfactory compression strength. Research limitations/implications: The advantage of the bonded composite materials is their simple technology, possibility of forming their properties, lowering manufacturing costs because of no costly finishing and lowering of material losses resulting from the possibility of forming any shape. The manufacturing of composite materials greatly expand the applicable possibilities of nanocrystalline powders of magnetically hard materials. Originality/value: Manufacturing processes of hard magnetic composite materials obtaining Nd-Fe-B-polymer matrix.

2

New possibilities of application of composite materials with soft magnetic properties

86%

Ziębowicz B. , Szewieczek D. , Dobrzański L. A.

|

2007

|

tom Vol. 20, nr 1-2

207-210

EN

Purpose: The purpose of the paper is characteristic of properties and application possibilities of modern soft magnetic materials and to show the influence of them on the developed of modern technology in different branches of techniques. Another aspect involved in the paper is to present the material and technological solution which makes possible obtaining soft magnetic composite materials: nanocrystalline material - polymer type. Design/methodology/approach: The main base of the paper is to show the properties and possibilities of application of modern soft magnetic materials with taking into consideration the development of manufacturing technology of these materials which by obtaining the maximum possible values of properties allows for simplification of machines and devices construction with use of magnetic elements. Findings: Modern soft magnetic materials have optimum technology of production with properties that allow for miniaturizing, simplification and lowering the costs of devices. Practical implications: The usability of modern soft magnetic materials as inductive component in electronic industry depends upon further investigations. Originality/value: The paper is the review of modern magnetic materials development and shows the material and technological solution which make possible obtaining magnetic composite materials with assumed properties.

3

Corrosion of Nd-Fe-B permanent magnets

86%

Drak M. , Dobrzański L. A.

|

2007

|

tom Vol. 20, nr 1-2

239-242

EN

Purpose: purpose of the paper is to presents results of corrosion wear of bonded and sintered hard magnetic materials Nd-Fe-B and magnets covered by protective polymer, lacquer and metal coatings. Design/methodology/approach: Corrosion tests were made in two corrosive environments in water and in 5% NaCl solution. Findings: It was found that the bonded magnets with the polymer matrix demonstrate better corrosion resistance than the sintered magnets. Employment of the protective coatings on the Nd-Fe-B bonded magnets surfaces may feature the effective protection of the substrate material from the corrosive action of the aggressive agent. Practical implications: Magnets covered by protective polymer, lacquer or metal coating are less susceptible to corrosion so employment of these coatings can lower the losses caused by the corrosion of magnets. Corrosion protection of Nd-Fe-B magnets needs further investigations. Originality/value: Analysis of the surface topography of the deposited protective coatings makes it possible to determine coating defects resulting from the action of the aggressive agent. The obtained results can be use in practice to decrease the corrosion wear of these materials.

4

FMR study of magnetic nanoparticles embedded in non-magnetic matrix

86%

Guskos N. , Anagnostakis E. A. , Guskos A.

|

2007

|

tom Vol. 24, nr 1

26-35

EN

Purpose: The aim of this review is recapitulating the FMR study of low concentration of magnetic nanoparticles in non-magnetic matrices. Design/methodology/approach: Magnetic nanoparticles exhibit a variety of anomalous magnetic properties and they could be used for forming low concentration in different matrices. This way, they are being found to be allowing for effectively novel applications of FMR (ferromagnetic resonance) for easier trustworthy characterisation of a variety of materials. alpha-Fe, Co, Fe3C, gamma- Fe203, Fe3O4 magnetic nanoparticles have been used as low concentration fillers in paraffin, concrete, resin and polymers/copolymers. Findings: For all these matrices, the intensities of the FMR spectra are recorded decreasing with temperature lowering in the high temperature region, whilst the resonance locus is shifted to the direction of lower magnetic field, essentially changing the resonance condition. These parameters of the FMR spectra are seen depending upon kind of a nanoparticle host in such a way that this method could be useful for studying dynamical processes of the matrices. Interestingly enough, a very low concentration of magnetic nanoparticles embedded in the non-magnetic matrix could modify its glass-state emanation or melting transition. Research limitations/implications: Composite systems containing magnetic nanoparticles promise the potential for high-density data storage, biomedical applications, catalysis, and nanotechnology sensor materialisation among other envisaged utilisations. Originality/value: Continue attempting to decipher the mystery and fruitfulness of magnetic nanoparticle distributions.

5

3D Measurement and Modelling of Magnetic Properties of Soft Magnetic Composite

86%

Zhu J. , Lin Z. , Guo Y. , Huang Y.

|

2009

|

tom R. 85, nr 1

11-15

EN

The soft magnetic composite (SMC) is a new type of soft magnetic material made of insulated iron powders. Its special characteristics could enable the development of low cost high performance electrical machines. This paper presents the measurement and modelling of magnetic properties of SMC under 3D magnetizations. Detailed descriptions of the 3D magnetic property tester, principle of measurement, core loss models, and experimental results are included and discussed.

PL

Magnetycznie miękkie kompozyty (soft magnetic composites – SMC) są nowym rodzajem magnetycznie miękkich materiałów wykonanych z elektrycznie izolowanych cząsteczek proszku żelaza. Specjalne charakterystyki takich materiałów mogą umożliwić rozwój tanich i wydajnych maszyn elektrycznych. Artykuł prezentuje pomiary i modelowanie własności magnetycznych SMC w warunkach przemagnesowania 3D. Podano dokładny opis użytej techniki pomiarowej, modelu i wyników pomiarowych.

6

Hard magnetic materials Nd-Fe-B/Fe with epoxy resin matrix

86%

Drak M. , Dobrzański L. A.

|

2007

|

tom Vol. 24, nr 2

63-66

EN

Purpose: The purpose of the paper is to present the technological solution of obtaining hard magnetic composite materials based on Nd-Fe-B with addition of iron powder and bounded by epoxy resin. Design/methodology/approach: Composite materials reinforced by Nd-Fe-B particles or Nd-Fe-B with addition of iron powder with polymer matrix were manufactured by one-sided uniaxal pressing. The complex relationships among the manufacturing technology of these materials, their microstructure, as well as their magnetic and mechanical properties were evaluated. Findings: This kind of composite materials can broader the possibilities of application of magnetic materials and reduce the cost of their manufacturing. Practical implications: The manufacturing of hard magnetic composite materials by addition of other powder and bounding them by polymer matrix can greatly extend the applicable possibilities of these materials. There are still made investigations that allow to improve properties of hard magnetic composite materials and influence on the miniaturization of magnets and devices they are used in. Originality/value: The paper shows the technological solution which make it possible obtaining hard magnetic composite materials, their structure and properties.

7

Dynamic vector magneto-hysteretic E&S model taking into account of eddy current effect

86%

Urata S. , Enokizono M.

|

2007

|

tom R. 83, nr 4

1-8

EN

This paper deals with the dynamic vector magnetic hysteretic engineering model, “Dynamic E&S Model”, which can analyze the effect of eddy current under the vector magnetic behavior. It is well known that the vector of magnetic field strength H is not always parallel to the magnetic flux density B in the core. Furthermore when the wave of magnetic flux is distorted, the eddy current occurs. We will report the dynamic magnetic characteristic analysis taken care of eddy current.

PL

Artykuł omawia wektorowe modelowanie właściwości dynamicznych materiałów magnetycznych, nazwane “Dynamiczny model E&S”. Model ten umożliwia analizę wpływu prądów wirowych na wektorowe właściwości dynamiczne materiałów magnetycznych. Wiadomo, że w materiałach magnetycznych kierunek wektora pola magnetycznego nie zawsze jest równoległy do kierunku indukcji. Ponadto prądy wirowe pojawiają się gdy strumień magnetyczny jest odkształcony. W artykule analizuje się wpływ prądów wirowych na właściwości dynamiczne.

8

Materiały amorficzne i nanokrystaliczne w konstrukcjach przekładników prądowych

72%

Rajchert R.

|

2008

|

tom z. 116

13-20

PL

W obecnej dobie błyskawicznego postępu techniki, aby spełnić oczekiwania odbiorców, opracowywane są nowe materiały, dzięki którym nie tylko można poprawić jakość wyrobów, ale także znacznie zmienić ich parametry techniczne i gabarytowe.

EN

In the article there presented properties of amorphous and nanocrystalline materials used in electrotechnics. Especially it paid attention on a usability of these materials in magnetic circuits of current transformers.

9

Ocena odporności korozyjnej w roztworze sztucznej śliny materiału Nd10Fe84B6 wytwarzanego metodą mechanicznej syntezy

72%

Klimecka-Tatar D. , Pawłowska G.

|

2012

|

tom nr 4

152-155

PL

W pracy zbadano wpływ czasu mielenia stopu Nd10Fe84B6 na odporność korozyjną magnesów neodymowych w środowisku imitującym środowisko jamy ustnej. Dokonano analizy struktury magnesu na bazie proszku Nd10Fe84B6 po 10, 48 i 90-godzinnym procesie mechanicznej syntezy. Na podstawie badań rentgenograficznych zidentyfikowano fazy występujące w strukturze magnesu. Stwierdzono, że prócz podstawowej fazy ferromagnetycznej Nd2Fe14B występują również dwie fazy magnetycznie miękkie, faza Fealfa oraz faza Nd2Fe17. Oceny odporności korozyjnej magnesów dokonano na podstawie potencjokinetycznych krzywych polaryzacji w roztworze sztucznej śliny. Badania korozyjne wykazały, że wydłużony proces mechanicznej syntezy (90 h) i związane z nim rozdrobnienie struktury spowalnia szybkość korozji magnesów.

EN

In paper the effect of milling time of Nd10Fe84B6 alloy on corrosion resistance of neodymium magnets in an environment simulating the oral cavity was carried out. The analysis of structure magnets based on Nd10Fe84B6 powder after 10, 48 and 90-hours of mechanical alloying process was performed. On the basis of X-ray analysis three phases occurring in the magnet structure were identifi ed. It was found that besides the basic ferromagnetic phase Nd2Fe14B also two phases: soft ferromagnetic alfa-Fe phase and Nd2Fe17 phase in the material structure are present. To evaluate the corrosion resistance of the magnets potentiokinetic polarization curves in a solution of artifi cial saliva were measured. Corrosion tests have shown that prolonged mechanical alloying (90 h), and thus the fragmentation of the structure effectively slows the rate of corrosion of the magnets.

10

Materiały magnetyczne, ich właściwości i zastosowanie w magnetowodach

72%

Rajchert R. , Kuczałek B.

|

2006

|

tom z. 110

9-20

PL

Druga połowa XIX wieku charakteryzowała się szybkim rozwojem elektrotechniki. Zwiększało się zapotrzebowanie na energię elektryczną i wzrastała potrzeba przesyłu energii na znaczne odległości. Możliwość przesyłu energii przy prądzie stałym była ograniczona ze względu na duże straty. Dopiero wprowadzenie prądu zmiennego umożliwiło transformację energii o określonym napięciu i przesyłanie jej na dalsze odległości. Przekształcenie energii elektrycznej na inne wartości prądu i napięcia stało się możliwe dzięki zastosowaniu transformatorów, w których uzwojenia pierwotne i wtórne były sprzężone rdzeniami magnetycznymi. Własności magnetyczne materiałów używanych na rdzenie transformatorów decydowały o możliwościach transformacji i jej jakości. Aby poprawić parametry materiałów magnetycznych rdzeniowych, modyfikowano technologię ich wytwarzania, zmieniano skład, a także sposób obrabiania. Nieustannie prowadzone są w tym kierunku prace badawcze i dzięki temu powstają nowe generacje materiałów magnetycznych o coraz lepszych parametrach.

EN

The article presents issues in the development of magnetic materials used in electrotechnics. It pays particular attention to the change of the properties of magnetic materials used in current and voltage transformer cores and the use of different technologies in the production of these materials. It characterizes different kinds of core constructions and the changes in their magnetic peculiarities and the influence of these changes on the parameters of working transformers.

11

Charakterystyki nowych materiałów magnetycznych w ciekłym azocie do transformatorów HTS

72%

Stępień M. , Grzesik B.

|

2010

|

tom z. 2

69-78

PL

W artykule opisano charakterystyki B-H trzech amorficznych materiałów magnetycznych zmierzone w temperaturze LN2 oraz w temperaturze pokojowej. Proponowanym zastosowaniem są rdzenie transformatorów HTS. Charakterystyki zmierzono przy 50 Hz przyrządem Remacomp oraz przy wyższych częstotliwościach zasilając cewkę z rdzeniem z falownika DE. Pomiary przy wyższych częstotliwościach są dokładniejsze ze względu na wyższy poziom mocy. Wyniki potwierdzają dobre właściwości badanych materiałów do proponowanego zastosowania.

EN

The paper presents B-H characteristics of three amorphous magnetic materials measured at LN2 temperature and at room temperature. The proposed application of the tested materials are magnetic cores of HTS transformers. The characteristics were measured at 50 Hz with use of a Remacomp meter and at higher frequencies when supplying the coil and magnetic core by a DE inverter. The measurement results obtained at higher frequencies are more precise because of higher level of power losses. The results confirm good properties of the investigated materials for the proposed application.

12

From magnetite ore to modern magnetic materials.

58%

Wysłocki J. J.

|

2006

|

tom Vol. 27, nr 2-3

67-84

EN

The article describes the major stages of research on magnetic materials carried out over the centuries, which have contributed to the discovery and further understanding of new materials. In relation to the above results of investigations carried out in recent years at the Institute of Physics of the Częstochowa University of Technology, concerning the determination of the sources of the magnetic properties and the mechanisms of magnetization of magnetically hard materials, in conjunction with the observations of the domain structure, are presented. Moreover, further interesting results have been obtained from the investigation of the microstructure and magnetic properties of magnetically soft materials - amorphous and nanocrystalline films. New technologies for the production of magnetic materials using the arc-plasma spraying technique and the suction-casting method enabling the production of massive amorphous alloys (bulk amorphous magnetic materials) are also described.