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1

The use of DSC curves and the Kronmüller theory to study the level of structural defects of Fe-based bulk amorphous alloys

Jeż Bartłomiej, Nabiałek Marcin

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 2

art. no. e144613

EN

This article presents the results of tests carried out on rapid quenched Fe-based alloys. The alloys were made using an injection-casting method. The actual structure of the alloys was also studied using an indirect method, based on H. Kronmüller's theorem. Based on analysis of the primary magnetization curves, in accordance with the aforementioned theory, it was found that Mo causes a change in internal regions associated with changes in the direction of the magnetization vector. The evolution of the thermal properties with increasing volume of Mo has been confirmed by the DSC curves. Addition of Mo, at the expense of the Nb component, results in changes to the crystallization process (i.e. the crystallization onset temperature and number of stages). The study showed that the addition of Mo at the expense of Nb reduces glass forming ability. Based on the DSC analysis, free volumes were determined for the alloys tested. These values were compared with the analysis of primary magnetization curves. It was found that the DSC curves can be used to indirectly describe the structure of amorphous alloys similar to the theory of the approach to ferromagnetic saturation. This approach is new and can be used by many researchers in this field.

2

The structure and properties of magnetic composites based on amorphous Fe alloys

Jeż Bartłomiej, Postawa Przemysław, Nabiałek Marcin

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 4

art. no. e144608

EN

Materials with so-called soft magnetic properties are an important object of material engineering research due to their potential application, among others, in the construction of low-loss transformer cores. Such properties are typical for alloys with an amorphous structure and with a high content of ferromagnetic elements: Fe, Co, Ni. Difficulties related with obtaining alloys which meet satisfactory dimensions result in the search for new solutions. One of them is the production of composites based on ferromagnetic powders obtained from amorphous alloys. This paper presents results of structure research for composite materials produced in a multi-stage production process. Magnetic composites were made on the basis of a bulk amorphous Fe70B20Y5Nb4Mo1 alloy produced by the injection method. On the basis of the obtained powder, two series of moldings were made: with 0.5% resin and covered with high-temperature varnish. Final composites were produced by using high temperature isostatic press. On the basis of the conducted research, it was found that the composites without resin are characterized by distinctly better magnetic properties as compared to resin-bonded composites.

3

Reduced Glass-Transition Temperature versus Glass-Forming Ability in FeCoB-Based Amorphous Alloys

Nabiałek M.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 4

1957--1962

EN

This work presents studies concerning the relationship between reduction of glass transition temperature Trg and the glass-forming ability of FeCoB-based alloys. On the basis of theoretical considerations, Turnbull [1] determined the reduced glass transition temperature (Tg/Tl) as being 2/3 of the Vogel–Fulcher–Tammann (VFT) temperature; since then, continuous research has been carried out, aiming to calculate the Trg parameter and describe its relationship with glass-forming ability. In the majority of research papers, the reduced glass transition temperature is calculated from the relationship Tg/Tm, proposed by Uhlmann and Davies [2, 3]. On the basis of differential scanning calorimetry (DSC) studies, undertaken in this current work, the values of the following temperatures have been found: Tg, Tx, Tm and Tl, in addition to the temperature ranges: ΔTx, ΔTm and ΔTl. The correlation between: Tg/Tm, Tg/Tl and the glass-forming ability also has been discussed. Finally, for the investigated alloys, it has been found that the relationship proposed by Turnbull is reliable over a wide range of ΔTm.

4

Crystallization of Fe-Based Bulk Amorphous Alloys

Błoch K., Dośpiał M., Garus S.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 1

7--10

EN

The aim of this paper is to present the results of crystallization studies for the bulk amorphous (Fe0.61Co0.10Zr0.025Hf0.025 Ti0.02W0.02B0.20)98Y2, Fe61Co10TixY6B20, Fe61Co10Ti2Y7B20 alloys. The crystallization of the alloys was studied by differential scanning calorimetry (DSC). The amorphicity of the investigated alloys in the as-quenched state was testified using Mossbauer spectroscopy, X-ray diffractometry and transmission electron microscopy. Moreover, X-ray diffractometry was applied to structure investigations of partially crystallized samples. The crystallization process in the investigated alloys occurs in one or two stages. Two peaks in the DSC curves can be overlapped or well separated indicating the complex crystallization processes. From X-ray diffraction we have stated that in both types of devitrification the crystalline phase can be ascribed to the α-FeCo. In the first stage the crystalline grains seem to grow from the nuclei frozen in the samples during the rapid quenching, whereas in the second one both the growth of the existed grains and creation of new ones during annealing may occur.

PL

W pracy przedstawiono wyniki badań krystalizacji masywnych stopów amorficznych (Fe0.61Co0.10Zr0.025Hf0.025 Ti0.02W0.02B0.20)98Y2, Fe61Co10TixY6B20, Fe61Co10Ti2Y7B20 w postaci prętów. Krystalizację tych stopów badano wykorzystując skaningowy kalorymetr różnicowy (DSC). Amorficzność próbek w stanie po zestaleniu została zbadana przy użyciu spektroskopii Mössbauera, dyfrakcji promieni Röntgena oraz transmisyjnej mikroskopii elektronowej. Ponadto, dyfrakcję promieni X użyto do badań próbek częściowo skrystalizowanych. Na podstawie badań z wykorzystaniem DSC stwierdzono, że krystalizacja może przebiegać w jednym lub w dwóch etapach. Piki na krzywych DSC odpowiadające tym dwóm etapom mogą być położone blisko siebie lub wyraźnie rozdzielone. Pierwsze maksimum odpowiada tworzeniu się ziaren α-FeCo z zarodków powstałych podczas produkcji stopu, drugie natomiast związane jest z procesem tworzenia się ziaren fazy krystalicznej α-FeCo z zarodków powstałych podczas wygrzewania i rozrostem wcześniej powstałych ziaren.

5

The influence of resin content on the mechanical and soft magnetic properties of composite prepared on the basis of the bulk amorphous materials

Błoch K., Nabiałek M., Szota M.

Inżynieria Materiałowa

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2014

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Vol. 35, nr 2

82--85

EN

The paper presents studies of microstructure, magnetic and mechanical properties of composite prepared on the basis of the bulk amorphous materials. The results presented in this work indicate, that it is possible to generate electrotechnical composite material having a rather high microhardness, which are built in more than 95 wt % of amorphous ferromagnetic metal powder, and the remaining part is Epidian 100 resin. Examined composites were fully amorphous and homogeneous. The homogeneity of the material from which ferromagnetic particles are prepared for composites is an important parameter, which ensures the same properties throughout the entire volume of the composite. Combination of amorphous particles of fraction 100÷200 microns, with the polymeric binder, resulted in a microhardness reduction in relative to the bulk amorphous plate. With increasing weight content of the resin, in the composite, the saturation magnetization significantly decreased, while the coercivity field increased over twentyfold.

PL

W pracy przedstawiono wyniki badań struktury, właściwości magnetycznych i mechanicznych przeprowadzonych dla kompozytów wytworzonych z amorficznych cząstek połączonych żywicą epoksydową. Otrzymane wyniki wskazują, że jest możliwość wytworzenia elektrotechnicznego materiału kompozytowego o dość dużej mikrotwardości zbudowanego w ponad 95% z ferromagnetycznego metalicznego amorficznego proszku, resztę stanowi żywica epidian 100. Badane materiały kompozytowe były w pełni amorficzne i homogeniczne, co oznacza, że rozdrobniony materiał uzyskany z amorficznych płytek miał dobrą jednorodność. Jednorodność materiału, z którego wytwarza się cząstki ferromagnetyczne dla kompozytów jest istotnym parametrem, zapewniającym zachowanie takich samych właściwości w całej objętości kompozytu. Zespolenie amorficznych cząstek o frakcji 100÷200 μm polimerowym lepiszczem wpłynęło na obniżenie mikrotwardości w porównaniu z próbką w postaci płytki. Wraz ze wzrostem zawartości żywicy w kompozycie znacznie zmniejszyła się magnetyzacja nasycenia, natomiast pole koercji wzrosło ponad dwudziestokrotnie.

6

Improvement of mechanical properties of Fe-based alloys by application of rapid solidification method and Ti doping

Gondro J., Błoch K., Nabiałek M., Dośpiał M., Szota M., Bukowska A., Pietrusiewicz P.

Inżynieria Materiałowa

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2014

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Vol. 35, nr 2

127--131

EN

The results of research into the microstructure and mechanical properties of Fe73T5Y3B19, Fe61Co10Y8Ti1B20 alloys are presented in this paper. Samples were obtained at the solidification speed of 104÷106 K/s in the form of ribbons of about 30 µm in thickness. All studies were conducted for samples in the as-cast state. Amorphous structure of the investigated alloys was confirmed by the X-ray diffractometry. The chemical composition determined from EDS studies was similar to the nominal composition of the alloy. Photos of the Vickers imprints, and the abrasion areas were obtained using an optical microscope for the matte side of the tape. The obtained results showed that the alloy with higher titanium content had much higher abrasion resistance as well as greater surface development.

PL

W pracy przedstawiono wyniki badań mikrostruktury oraz wybranych właściwości mechanicznych stopów Fe73T5Y3B19, Fe61Co10Y8Ti1B20 otrzymanych przy prędkości krzepnięcia 104÷106 K/s w postaci cienkich taśm o grubości około 30 µm. Badania przeprowadzono dla próbek stopów w stanie po zestaleniu. Amorficzność stopów potwierdzono badaniami rentgenowskimi. Skład chemiczny próbek został wyznaczony na podstawie badań z wykorzystaniem spektrometru rentgenowskiego EDS i jest zbliżony do nominalnego składu stopu. Zdjęcia próbek, odcisków Vickersa oraz obszarów wytarć wykonano z wykorzystaniem mikroskopu świetlnego. W pracy przedstawiono wyniki badań dla matowej strony taśmy. Wyniki badań zamieszczone w tej pracy pokazują, że stop z większą zawartością tytanu cechuje się znacznie większą odpornością na ścieranie, jak również większym rozwinięciem powierzchni.

7

The Structural Stability of the Fe36 Co36 Si19 B5 Nb4 Bulk Amorphous Alloy

Nabiałek M., Pietrusiewicz P., Szota M., Dobrzańska-Danikiewicz A., Lesz S., Dośpiał M., Błoch K., Oźga K.

Archives of Metallurgy and Materials

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2014

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Vol. 59, iss. 1

259--262

EN

In this paper, the results of the investigation into the fractured surface microstructure of the amorphous samples of Fe36 Co36 Si19 B5 Nb4 in the shape of rods of diameters: 1 mm, 2 mm and 3 mm in the as-cast state are presented. The samples were prepared by injection of molten alloy into cooled copper dies. The process of diffusion in the investigated material has a different speed depending on the temperature gradient within the volume of the rod. The atomic diffusion leads to the creation of different zones within the rod fracture: the zone in contact with the copper die, the intermediate fracture zone, and the zone in the vicinity of the rod core; the three zones have been found to exhibit different amorphous structures.

PL

W pracy przedstawiono wyniki badań mikrostruktury na powierzchni przełomów próbek Fe36 Co36 Si19 B5 Nb4 amorficznych w postaci prętów o średnicy 1 mm. 2 mm i 3 mm. w stanie po zestaleniu. Pręty wytworzono metodą wtłaczania ciekłego stopu do miedzianej, chłodzonej cieczą formy. Proces dyfuzji atomów w badanym materiale charakteryzuje się inną dynamiką w zależności od gradientu temperatury w objętości pręta. Wyróżnia się trzy wyraźnie widoczne strefy: od kontaktu z miedzianą formą, strefę przejściową oraz strefę opisującą rdzeń pręta. Każdą z wyróżnionych stref charakteryzują różne konfiguracje atomów w zakresie stanu amorficznego. Na podstawie badań stwierdzono, że w masywnych materiałach amorficznych występuje fluktuacja składu oraz gęstości w zależności od szybkości chłodzenia.

8

Effect of Cooling Rate on Magnetic Properties, Size and Type of Structural Defects in the Volume of Bulk Amorphous Fe36 Co36 B19 Si5 Nn4 Alloy in the Form of Rods of Various Diameters

Nabiałek M., Dobrzańska-Danikiewicz A., Lesz S., Pietrusiewicz P., Szota M., Dośpiał M.

Archives of Metallurgy and Materials

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2014

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Vol. 59, iss. 1

263--268

EN

This paper presents the results of microstructure and magnetic properties analysis for bulk amorphous samples of Fe36 Co36 B19 Si5 Nn4 alloy in the form of rods of 1 mm, 2 mm, and 3 mm diameters in the as-cast state, produced using the method of injecting liquid alloy into cooled copper mold. The main purpose of the research was to examine the effect of solidification speed of the liquid material into amorphous state on the shape of initial magnetization curve as well as to determine the type and size of structural defects occurring in the volume of the material. In order to achieve these objectives, the magnetization measurements were carried out, which according to H. Kronmüller’s theory on magnetization behavior near the area called reaching the ferromagnetic saturation, allow to determine the type, size, and surface density of structural defects occurring in the volume of the sample. The analysis of reduced magnetization curves indicates that solidification speed of the liquid alloy into the amorphous state is the main determining factor for the shape of initial magnetization curve and for the type and size of structural defects formed in the sample, which affects such magnetic parameters as: coercive field (HC) or saturation magnetization (MS).

PL

W pracy przedstawiono wyniki badań mikrostruktury oraz właściwości magnetycznych masywnego stopu amorficznego Fe36 Co36 B19 Si5 Nn4 w stanie po zestaleniu. Próbki stopu zostały wytworzone w postaci prętów o średnicy 1 mm, 2 mm i 3 mm przy zastosowaniu metody wtłaczania ciekłego materiału do miedzianej formy chłodzonej wodą. Mikrostrukturę próbek w stanie po zestaleniu badano wykorzystując dyfrakcję promieni Rontgena. natomiast magnetyzację w silnych polach magnetycznych mierzono wykorzystując magnetometr wibracyjny (VSM). Głównym celem pracy było zbadanie wpływu czasu zestalania ciekłego materiału do stałego stanu amorficznego na przebieg pierwotnej krzywej magnesowania oraz określenie rodzaju i wielkości defektów strukturalnych występujących w badanych próbkach.

9

Structure and magnetic properties of bulk amorphous (Fe0.61Co0.10Zr0.025Hf0.025W0.02Ti0.02B0.20)94Y6 alloy

Błoch K.

Archives of Materials Science and Engineering

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2013

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Vol. 64, nr 2

97--102

EN

Purpose: The aim of this paper were studies of the structure and magnetic properties of the bulk amorphous (Fe0.61Co0.10Zr0.025Hf0.025W0.02Ti0.02B0.20)94Y6 alloy, obtained by suction-casting method. Design/methodology/approach: The microstructure of the as-quenched and annealed at 720K for 15 min samples was studied by X-ray diffractometry and Mössbauer spectroscopy. The transmission Mössbauer spectra for the powdered samples were measured at room temperature using conventional Mössbauer spectrometer working at a constant acceleration with a 57Co(Rh) radioactive source of the 70 mCi in activity. However, the low field magnetic properties such as magnetic susceptibility, its disaccommodation and core losses were measured by a transformer method using a completely automated set up. In susceptibiity and its disaccommodation studies the amplitude of the magnetizing field was 0.26 A/m. Before the measurements the samples were demagnetized in an alternating magnetic field with the amplitude decreasing from 800 A/m to zero during 1.1 s. The core losses and magnetic permeability as a function of the magnetizing field amplitude for the frequency up to 1 kHz were measured. Findings: The rods were fully amorphous which was confirmed by X-ray diffractometry and Mössbauer spectroscopy. On the basis studies of magnetization in high magnetic fields we have stated, that in investigated alloy, in the as-quenched state and after annealing, only structural defects called quasi-dislocation dipoles are present. The disaccommodation phenomenon in the investigated samples of (Fe0.61Co0.10Zr0.025Hf0.025W0.02Ti0.02B0.20)94Y6 alloy , related with the directional ordering of atomic pairs near the free volumes, is not observed. On the basis of the changes in core losses, it can be stated that the studied alloy at low frequencies the total losses are comparable with those observed in classical silicon-iron alloys. Practical implications: Using a vibrating sample magnetometer the magnetization in high magnetic fields was studied (in magnetic field up to 2 T). All investigations carried out for samples in the as-quenched state and after annealing. Originality/value: This paper presents studies relating to the structure and magnetic properties of the bulk amorphous (Fe0.61Co0.10Zr0.025Hf0.025W0.02Ti0.02B0.20) alloy, obtained in the form of rods with 2 mm in diameter and 2 cm long by the suction casting method

10

Arc-plasma spraying and suction-casting methods in magnetic materials manufacturing

Wysłocki J. J., Pawlik P.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 43, nr 1

463--468

EN

Purpose: The paper discusses two new technologies for producing magnetic materials which have been successfully developed in recent years at the Institute of Physics of the Czestochowa University of Technology and discusses properties of the materials obtained with the use of these methods. Design/methodology/approach: In this research the arc-plasma deposition of Nd2Fe14B powders onto a substrate either cooled with water or heated up to a temperature in the range from 773 to1023 K was applied. In the second method the suction of an arc-melted alloy to a water-cooled copper mould (the suction-casting method) was introduced. Moreover, microstructure, magnetic properties and domain structure of the produced samples were determined. Findings: It has been found that thin Nd2Fe14B strips obtained by the plasma method possess magnetic properties. It has also been demonstrated that the suction-casting method makes it possible to obtain both amorphous magnetically soft materials (e.g. Fe-Co-W-Zr-B), as well as magnetically hard nanocomposites (e.g. (Fe-Co)-(Pr-Dy)-B-Zr). Research limitations/implications: The main problem in the suction-casting method is to reduce the critical cooling rate required for the production of amorphous alloys and to increase the geometrical dimensions of amorphous specimens. Practical implications: Thin-layered Nd-Fe-B magnets produced by means of arc-plasma deposition can be applied directly onto the surface of electromagnetic equipment parts. Magnets with isotropic magnetic properties were obtained by applying layers onto the water-cooled copper substrate. Whereas, anisotropic magnets were obtained as a result of the arc-plasma deposition of powders onto the copper substrate heated up to 873 K. The most advantageous properties were achieved for the microcrystalline structure of a grain size close to the single-domain particle size (approx. 0.3 μm). Moreover, it has been demonstrated that the suction-casting method makes it possible to obtain bulk amorphous alloys of considerable sizes, such as rods of magnetically soft Fe-Co-W-Zr-B alloys of a diameter up to 2 mm, as well as Fe-Co-Pr-Zr-B tubes of a diameter up to 3 mm. It is also possible to produce magnetically hard nanocomposite materials of the (Fe-Co)-(Pr,Dy)-B-Zr type by annealing of metallic glasses. Originality/value: Successfully introduced new methods of magnetic materials manufacturing.

11

Modeling of magnetic properties of bulk amorphous alloys using an artificial neural network tool

Szota M., Borkowski S., Nabiałek M.

International Journal of Applied Mechanics and Engineering

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2010

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Vol. 15, no 2

571-578

EN

This paper presents the possibility of using neural networks model for designing magnetic properties of bulk amorphous alloys. In recent years large quantity of data has been published about production methods of bulk metallic glasses (BMG). The most popular methods are: suction casting (Inoue and Tao, 1995; Ma et al., 2005) and injection casting (Park and Kim, 2004). From the microstructure investigation it was found that samples obtained as plates in contrast to rods have full amorphous microstructure. Samples as rods were partially crystallized. This process is complex and difficult as multi-parameter changes are non-linear. This fact and lack of mathematical algorithms describing this process make modeling properties of bulk amorphous-alloys by traditional numerical methods difficult or even impossible. In this case, it is possible to use an artificial neural network. Using neural networks for modeling is caused by several net features: non-linear character, the ability to generalize the results of calculations different from the learning data set, lack of need of mathematical algorithms describing influence of input parameters changes on modeling materials properties. The neural network structure is designed and specially prepared by choosing input and output parameters of the process. The method of neural network learning and testing, the way of limiting net structure and minimizing learning and testing error are discussed. Such a neural network model, after putting desirable values of bulk amorphous alloys properties in the output layer, can give answers to a lot of questions about production process. The practical implications of the neural network models are the possibility of using them to build control system capable of on-line process control and supporting engineering decision in real time. The originality of this research is a new idea to obtain desirable bulk amorphous alloys properties after crystallization process. The specially prepared neural network model could be a help for engineering decisions made in real time.

12

Structure and Soft Magnetic Properties of Bulk Amporphous (Fe0.61Co0.10Zr0.025W0.02Hf0.025Ti0.02B0.20)96Y4 Alloy

Gondro J., Zbroszczyk J., Ciurzyńska W., Olszewski J., Nabiałek M., Sobczyk K., Świerczek J., Łukiewska A.

Archives of Metallurgy and Materials

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2010

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Vol. 55, iss. 1

85-90

EN

In this paper we present results of the structure and soft magnetic properties investigations for the bulk amorphous (Fe0.6iCoo.ioZr0.o25Wo.o2Hfo.o25Tio.o2Bo.2o)96Y4 alloy after the solidification and annealing at 720 K for 15 min. We have stated that the as-quenched alloy is fully amorphous. However, from Mossbauer studies we have found that after the annealing a smali amount of the grain nuclei in the sample occurs. The investigated alloy is a soft magnetic ferromagnet. It shows relatively high initial (higher than for crystalline soft magnetic materials) and maximum susceptibility and Iow core losses. Moreover, the magnetic susceptibility increases and core losses decrease after the heat treatment of the sample. It is due to the stress relieving of the sample. Additionally, this alloy is characterized by good thermal stability of the magnetic susceptibility.

PL

W pracy są prezentowane wyniki mikrostruktury oraz tzw. miękkich właściwości magnetycznych masywnego stopu amorficznego (Fe0.6iCoo.ioZr0.o25Wo.o2Hfo.o25Tio.o2Bo.2o)96Y4 w stanie po zestaleniu i po obróbce cieplnej w temperaturze 720 K przez 15 min. Na podstawie badań mosbauerowskich stwierdzono, że stop po zestaleniu jest w pełni amorficzny, natomiast po obróbce cieplnej w temperasturze 720 K przez 15 min. pojawia się niewielka ilość zarodków fazy krystalicznej. Badany stop jest ferromagnetykiem miękkim i wykazuje względnie dużą podatność początkową (wyższą niż miękkie magnetycznie materiały krystaliczne), dużą maksymalną podatnością magnetyczną i małe straty na przemagnesowanie. Po obróbce cieplnej, w wyniku odprężenia, próbki obserwuje się wzrost podatności magnetycznej i zmniejszenie strat na przemagnesowanie. Należy podkreślić, że stop (Fe0.6iCoo.ioZr0.o25Wo.o2Hfo.o25Tio.o2Bo.2o)96Y4 charakteryzuje się stabilnością termiczną podatności magnetycznej.

13

Microstructure, Some Magnetic and Mechanical Properties of Amorphous Fe60Co10Zr2.5Hf2.519W2Y2B21 Plates

Nabiałek M., Zbroszczyk J., Ciurzyńska W., Olszewski J., Lesz S., Brągiel P., Gondro J., Sobczyk K., Łukiewska A., Świerczek J., Piertusiewicz P.

Archives of Metallurgy and Materials

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2010

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Vol. 55, iss. 1

195-203

EN

In this paper we present the results of microstructure, thermal stability and magnetic properties studies for the bulk amorphous Fe6iCoioZr2.5Hf2.5W2Y2B2o alloy in the form of plates 0.5 mm in thickness prepared at different cooling rates (in a mould cooled with water and without cooling with water). We have stated that the investigated alloy exhibits good glass-forming ability. The amorphous plates obtained at larger cooling ratę show a slightly higher crystallization temperaturę. SEM micrographs on the fraction surface of the plates reveal parallel and curved bands. The chemical composition on the fraction surface determined from EDS studies is close to the nominał composition of the alloy. The amorphous plates prepared at larger cooling ratę exhibit better soft magnetic properties.

PL

W pracy przedstawiono wyniki badań mikrostruktury, stabilności termicznej i właściwości magnetycznych masywnego stopu amorficznego Fe6iCoioZr2.5Hf2.5W2Y2B2o w postaci płytek o grubości 0,5 mm. Próbki przygotowano techniką szybkiego chłodzenia (w formie chłodzonej wodą i bez chłodzenia). Otrzymany stop wykazywał dobrą zdolność do zeszklenia. Amorficzne płytki wytworzone z większą szybkością chłodzenia cechowały się nieco wyższą temperaturą krystalizacji. Na obrazach struktury przełomów płytek uzyskanych za pomocą mikroskopu skaningowego widoczne są liniowe równoległe i zakrzywione pasma. Analizę chemiczną składu stopu wykonano metodą EDS, skład otrzymanych próbek był zgodny ze składem nominalnym. Amorficzne płytki wykonane z dużą szybkością chłodzenia wykazywały lepsze miękkie właściwości magnetyczne.

14

Surface and bulk properties of thick amorphous iron alloys

Nabiałek M., Sobczyk K., Gondro J., Gwoździk M., Szota M.

Optica Applicata

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2009

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Vol. 39, nr 4

781-785

EN

The microstructure and mechanical properties, such as hardness and abrasive resistance, for the amorphous Fe60Co5Zr8Mo5W2B20 samples in the form of plate and rod have been investigated. We have stated that the samples obtained by a suction-casting method were fully amorphous. Moreover, from Mössbauer spectroscopy studies we have found that the amorphous rod is more homogenous than the plate. It is due to different quenching rates in the layers located near the surface and inside the samples. Hardness on the side surface of the plate or rod are almost the same in different measured points. However, hardness in the cross-section of the rod exhibits the maximum value near its surface. It is worth noticing that hardness of the amorphous samples is about twofold larger than for crystalline ingots. Wear resistance of the outer layer is smaller than for layers located near the centre of the sample.

15

Microstructure, magnetic properties and crystalization behaviour of bulk amorphous Fe61Co10Zr2.5Hf2.5Ni2W2B20 alloy

Sobczyk K., Zbroszczyk J., Nabiałek M., Olszewski J., Brągiel P., Świerczek J., Ciurzyńska W., Łukiewska A., Lubas M., Szota M.

Archives of Metallurgy and Materials

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2008

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Vol. 53, iss. 3

855-859

EN

Microstructure by X-ray diffractometry and Mo ssbauer spectroscopy and some magnetic properties such as magnetic polarization curves, magnetic permeability, total core losses and approach to magnetic saturation for the bulk amorphous Fe61Co10Zr2.5Hf2.5Ni2W2B20 alloy in the as-quenched state and after heat treatment at 850 K for 15 min are studied. The as-cast samples in the form of plates are fully amorphous and after annealing the samples are partially crystallized. The grains of Fe80Co20 and disordered Fe3B phases with the volume fraction each of 0.05 are embedded in the amorphous matrix which is much morę inhomogeneous than in the as-quenched state. The maximum magnetic permeability measured at 50 Hz and the magnetic saturation polarization increase from 1700 and 1.25 T in the as-cast state to 1800 and 1.47 T after heat treatment, respectively. The rotation of magnetic moments in the vicinity of point-like defects plays the decisive role in approach to ferromagnetic saturation in the as-quenched sample, whereas in the annealed sample the rotation of magnetic moments near the quasi-dislocation dipoles seems to be dominant. It indicates that during annealing the agglomeration of point-like defects takes place.

PL

Badano mikrostrukturę, wykorzystując dyfrakcję promieniowania X oraz spektroskopię móssbauerowską oraz niektóre właściwości magnetyczne, takie jak: polaryzację magnetyczną przenikalność, straty całkowite na przemagnesowanie oraz podejście do ferromagnetycznego nasycenia dla masywnego stopu Fe61Co10Zr2.5Hf2.5Ni2W2B20 w stanie po zestaleniu i po obróbce cieplnej w 850 K przez 15 min. Próbki w kształcie płytek w stganie po zestaleniu są amorficzne, natomiast po wygrzaniu są częściowo skrystalizowane. Ziarna fazy Fe80Co20 i nieuporządkowanej Fe3B o ułamku objętościowym 0.05 są umieszczone w matrycy amorficznej, która jest bardziej niejednorodna niż w stanie po zestaleniu. Maksymalna przenikalność magnetyczna mierzona przy częstości pola magnesującego 50 Hz i wartość magnetycznej polaryzacji nasycenia wzrastają odpowiednio z 1700 i 1.25 T w stanie po zestaleniu do 1800 oraz 1.47 T po obróbce cieplnej. Proces magnesowania w pobliżu ferromagnetycznego nasycenia w próbce po zestaleniu zachodzi głównie poprzez obrót momentów magnetycznych w pobliżu defektów punktowych, natomiast w próbce poddanej obróbce cieplnej - poprzez obroty momentów magnetycznych w pobliżu pseudo - dyslokacyjnych dipoli. Podczs wygrzewania próbki następuje aglomeracja defektów punktiwych i tworzą się pseudo-dyslokacyjne dipole.

16

Nowe technologie wytwarzania materiałów magnetycznych

Wysłocki J. J., Pawlik P.

Hutnik, Wiadomości Hutnicze

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2006

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Vol. 73, nr 6

280-284

PL

Przedstawiono dwie nowe technologie wytwarzania materiałów magnetycznych: łukowo-plazmowe nanoszenie proszków oraz zasysanie roztopionego łukowo stopu do chłodzonej wodą formy (suction-casting). Zbadano magnetyczne i strukturalne właściwości cienkich warstw Nd-Fe-B nanoszonych plazmowo na podłoże miedziane o różnej temperaturze. Ponadto pokazano, że metoda suction-casting pozwala na uzyskiwanie zarówno amorfcznych materiałów magnetycznie miękkich (np. Fe-Co-W-Zr-B), jak i nano-kompozytów magnetycznie twardych, np. (Fe-Co)-(Pr-Dy)-B-Zr.

EN

New two technologies of the magnetic materials manufacturing are presented: arc-plasma spraying and suction casting. Thin Nd-Fe-B flms prepared by arc-plasma spraying at different substrate temperatures were investigated for their magnetic and structural properties. Moreover, it is shown that the suction-casting method is suitable for manufacturing of magnetically soft amorphous materials (e.g. Fe-Co-W-Zr-B) as well as hard nanocomposites, e.g. (Fe-Co)-(Pr-Dy)-B-Zr.

17

Processing of bulk amorphous alloys by suction-casting method

Pawlik P., Nabiałek M., Żak E., Zbroszczyk J., Wysłocki J. J., Olszewski J., Pawlik K.

Archiwum Nauki o Materiałach

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2004

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T. 25, nr 3

177-184

EN

The processing of Fe-based bulk glassy alloys is presented. The bulk glassy samples were produced by the suction-casting unit integrated with the controlled atmosphere arc-melting furnace. The system was designed and constructed at the Institute of Physics, Częstochowa University of Technology. The X-ray diffactometry and Moessbauer spectroscopy were applied the confirm the amorphous structure of the processed alloys.

PL

W pracy przedstawiono proces wytwarzania masywnych stopów amorficznych na bazie żelaza. Masywne szkła metaliczne wytwarzano przy użyciu układu typu suction-casting zintegrowanego z piecem łukowym o kontrolowanej atmosferze ochronnej. Układ zaprojektowano i zbudowano w Instytucie Fizyki Politechniki Częstochowskiej. Badania rentgenowskie i moessbauerowskie wykazały istnienie struktury amorficznej wytwarzanych stopów.