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1

Microstructure and mechanical properties of amorphous/crystalline ductile liquid immiscible Fe-Si-B-In alloy produced by two-component melt-spinning

Ziewiec K., Wojciechowska M., Mucha D., Ziewiec A.

Metallurgy and Foundry Engineering

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2017

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Vol. 43, no. 1

57--66

EN

The two-component melt-spun (TCMS) Fe71.25Si9.5B14.25In5 alloy was produced from Fe75Si10B15 and Fe67.5Si9B13.5In10 alloys. The microstructure of the TCMS alloy was investigated by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). A tensile test of the alloy resulted in a tensile strength of Rm = 1040 MPa, yield strength Re= 919 MPa, total plastic elongation ɛtot = 3.29%, and traces of plastic deformation on the surface of the Fe-Si-B-In TCMS sample. Microstructural analysis of the amorphous/crystalline composite and tensile sample free surface show the reason for the ductility of the sample in relation to the Fe75Si10B15 alloy.

PL

Stop Fe71,25Si9,5B14,25In5 wytworzono w wyniku odlewania z tygla dzielonego na wirujący walec miedziany dwóch stopów (metoda TCMS): Fe75Si10B15 i Fe67,5Si9B13,5In10. Mikrostrukturę stopu TCMS badano za pomocą skaningowego mikroskopu elektronowego oraz dyfraktometru rentgenowskiego. Z przeprowadzonej statycznej próby rozciągania uzyskano wytrzymałość na rozciąganie stopu Rm= 1040 MPa, granicę plastyczności Re= 919 MPa, wydłużenie całkowite εtot = 3,29 %. Na powierzchni próbki stopu Fe-Si-B-In TCMS po zerwaniu zaobserwowano także ślady odkształcenia plastycznego. Analiza mikrostruktury otrzymanego amorficzno-krystalicznego kompozytu oraz powierzchni swobodnej próbki wyjaśniają przyczynę ciągliwości próbki w stosunku do stopu Fe75Si10B15.

2

Wytwarzanie przyrostowe stopów amorficznych metodą selektywnego stapiania laserowego

Żrodowski Ł., Wysocki B., Błyskun P., Wróblewski R., Kurzydłowski K.J., Święszkowski W.

Mechanik

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2017

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R. 90, nr 1

50--51

PL

W artykule opisano proces optymalizacji stapiania proszków szkła metalicznego na bazie żelaza. Stapianie prowadzono przy różnych parametrach mocy lasera i strategiach przyrostowego wytwarzania – tak, aby uzyskać wysoką zawartość fazy amorficznej. Wyniki badań potwierdzają istotny wpływ mieszania jeziorka ciekłego metalu oraz szybkości nagrzewania wierzchniej warstwy materiału na amorfizację.

EN

In the paper optimization process for selective laser melting of Fe-based metallic glass powder has been described. Melting process has been conducted with various laser power and parameters to increase materials amorphisation degree. Results showed strong influence of melt pool mixing and heating rate on amorphisation.

3

Struktura i zdolność do zeszklenia stopów Fe-Co-Zr-Mo-W-B domieszkowanych Gd

Kotynia K., Pawlik P., Hasiak M.

Hutnik, Wiadomości Hutnicze

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2017

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Vol. 84, nr 9

425--427

PL

W artykule przedstawiono wyniki badań stopów amorficznych Fe58Co10Zr10Mo5W2B15Gdx (x = 0, 1, 2, 3, 4, 5) wytworzonych w postaci taśm o grubości nie przekraczającej 35 μm. Badania strukturalne przeprowadzono za pomocą dyfrakcji rentgenowskiej (XRD), natomiast badania kalorymetryczne przy użyciu skaningowej kalorymetrii różnicowej (DSC). Głównym celem pracy była optymalizacja parametrów procesu wytwarzania szkieł metalicznych oraz określenie wpływu składu chemicznego stopów na ich zdolność do zeszklenia.

EN

The paper presents the results of research on the Fe58Co10Zr10Mo5W2B- 15Gdx (x = 0, 1, 2, 3, 4, 5) amorphous alloys produced fabricated in the form of the ribbon of the thickness below 35 μm. The X-ray diffraction (XRD) and the differential scanning calorimetry (DSC) have been employed in the structural and the thermal analysis examination respectively. The main objective of the study was to optimize the parameters of the metallic glasses fabrication process and to determine the effect of the alloys chemical composition on their glass forming ability.

4

Mechanical properties of Ni-Fe-Cu-P-B alloy produced by two component melt spinning (TCMS)

Wojciechowska M., Ziewiec K., Kąc S., Prusik K.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 1

137--140

EN

The aim of this work was to investigate the microstructure and mechanical properties of the two-component melt-spun (TCMS) alloy produced from Ni40Fe40B20 and Ni70Cu10P20 melts. The Ni40Fe40B20, Ni70Cu10P20, Ni55 Fe20 Cu5 P10 B10 alloys were arc-melted. Then the alloys were melt-spun in the two different ways i.e.: by casting from a single-chamber crucible and from the two-chamber crucible. All of the above mentioned alloys were processed in the first way and the Ni40Fe40B20 and Ni70Cu10P20 were simultaneously cast on the copper roller from the two-chamber crucible. The microstructure of the alloy was studied using transmission electron microscopy (TEM), scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS) and light microscopy. The mechanical properties were investigated using tensile testing and nanoindentation. The two-component melt-spun (TCMS) amorphous Ni55 Fe20 Cu5 P10 B10 alloy present hardness, tensile strength and Young modulus on the significantly higher level than for a single phase amorphous Ni55 Fe20 Cu5 P10 B10 alloy and slightly below the corresponding values for the Ni40Fe40B20.

5

Effect of surface coating with palladium on hydrogen permeability of Pd33Ni52Si15 amorphous alloy membrane

Prochwicz W., Macherzyński W., Paszkiewicz B., Stępień Z.

Optica Applicata

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2016

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Vol. 46, nr 2

173--179

EN

In the paper, the effect of the surface coating with palladium on hydrogen permeation of a Pd33Ni52Si15 amorphous alloy membrane was investigated. We have measured the hydrogen flow through the melt-spun amorphous membrane covered with palladium film of 10, 20, and 30 nm in thickness. Membranes have been tested in the temperature rage 294–358 K, and at pressure fixed at 102 kPa. We investigate the role of this film thickness on the activation energy for hydrogen permeability. It seemed that a relatively thin layer of the palladium on the surface of the membrane which contains over 30% of this element, should not considerably influence the permeability of the membrane for hydrogen. The membrane hydrogen permeability is correlated to permeation activation energy: the lower activation energy is, the higher permeability is observed. The activation energy for permeation strongly depends on palladium film thickness. The rapid increase of its value was recorded when the film thickness was growing up. As the result, the increase of the film thickness suppressed hydrogen permeability. Our findings are discussed in terms of a potential barrier between the two different phases.

6

Effect of Zr Purity and Oxygen Content on the Structure and Mechanical Properties of Melt-Spun and Suction-Cast Cu46Zr42Al7Y5 Alloy

Kozieł T., Latuch J., Cios G., Bała P.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 2B

1215--1219

EN

The effect of oxygen content in zirconium on the structure and mechanical properties of the Cu46Zr42Al7Y5 alloy, in the form of melt-spun ribbons and suction-cast rods, was investigated. Two types of Zr, rod and crystal bar of different nominal purities and oxygen contents, were used to synthesize the alloy by arc melting. Rapidly solidified ribbons were produced by melt spinning and their amorphous structures were confirmed by X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). Bulk samples in the form of rods were cast using a special water-cooled suction casting unit attached to the arc melting system. XRD and DSC studies proved the amorphous structure of the bulk alloy synthesized from low-oxygen Zr and partial crystallization of the same alloy for high-oxygen Zr. In both bulk samples, uniformly distributed crystalline particles were identified as yttrium oxides. Higher mean compressive strength of amorphous alloy was observed. The hardness of amorphous phase was close to 500 HV1 in both bulk alloys, while the hardness of crystalline dendritic areas, observed in the alloy synthesized from high oxygen Zr, was lower by about 50 HV1.

7

Subsurface structure and magnetic parameters of Fe-Mo-Cu-B metallic glass

Miglierini M., Hasiak M., Bujdoš M.

Nukleonika

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2015

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Vol. 60, No. 1

115--119

EN

Subsurface properties of 57Fe81Mo9Cu1B9 metallic glass were studied by conversion electron and conversion X-ray Mössbauer spectrometry. They were applied to both surfaces of the ribbons. Deviations in structural surface features are exhibited via different contents of crystalline phases, which were identifi ed as bcc-Fe and magnetite. The presence of small ferromagnetic particles was also suggested from magnetic measurements. An infl uence of irradiation with 130-keV N+ ions on surface properties of the as-quenched alloy is also discussed.

8

Hydrogen permeation properties of Pd-coated Pd33Ni52Si15 amorphous alloy membrane

Prochwicz W., Macherzyński W., Paszkiewicz B., Stępień Z. M.

Materials Science Poland

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2015

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Vol. 33, No. 1

56--58

EN

The vast majority of experimental techniques used for the measurements of hydrogen permeability through metallic membranes whose one or both surfaces are covered with a thin Pd film is based on the assumption that a ratio of film-to-membrane thickness is small enough to cause hydrogen flow to be independent of the Pd film thickness. In an attempt to verify this assumption, we have measured the hydrogen flow through the Pd33Ni52Si15 amorphous membrane covered with Pd film of 10, 20, and 30 nm in thickness. Contrary to our expectations, we have found a dramatic decrease in hydrogen flow with the increase in Pd film thickness. Our findings are discussed in terms of potential barrier between the two different phases.

9

CO Oxidation Properties Of Selective Dissoluted Metallic Glass Composites

Kim S. Y., Lee M. H., Kim T. S., Kim B. S.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2B

1227--1229

EN

Porous metallic materials have been widely used in many fields including aerospace, atomic energy, electro chemistry and environmental protection. Their unique structures make them very useful as lightweight structural materials, fluid filters, porous electrodes and catalyst supports. In this study, we fabricated Ni-based porous metallic glasses having uniformly dispersed micro meter pores by the sequential processes of ball-milling and chemical dissolution method. We investigated the application of our porous metal supported for Pt catalyst. The oxidation test was performed in an atmosphere of 1% CO and 3% O2. Microstructure observation was performed by using a scanning electron microscope. Oxidation properties and BET (Brunauer, Emmett, and Teller) were analyzed to understand porous structure developments. The results indicated that CO Oxidation reaction was dependent on the specific surface area.

10

The Structural Relaxation and its Influence on High Field Magnetization Processes

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

Archives of Metallurgy and Materials

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2014

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Vol. 59, iss. 2

659--662

EN

In this paper the results of the structural and magnetic investigation of Fe61Co10Y8Zr1B20 alloy after solidification and isothermal annealing was presented. The isothermical annealing was carried out at 700 K for 1 h and 770 K for 3.5 h. For the structural investigation was performed by X-ray diffractometer equipped with a copper lamp. The results of (XRD) measurements showed the material in the state after the solidification and heat treatment is amorphous. Static hysteresis loops and initial magnetization curve was measured using vibrating magnetometer (VSM). The quality and quantity of structural defects in the sample after heat treatment was determined by indirect method using analyze the initial magnetization curve in accordance with the theory of Kronmüllera. These studies have shown that the annealing process has big influence to change significantly quantity of defects in amorphous structure as a result, there are changes of magnetic parameters such as saturation magnetization and field μ0Ms coercivity Hc.

PL

W pracy przedstawiono wyniki badań strukturalnych i magnetycznych stopu Fe61Co10Y8Zr1B20 w stanie po zestaleniu oraz po izotermicznym wygrzewaniu w temperaturze 700 K przez 1h i 770 K przez 3,5 h. Badania struktury wykonano przy użyciu dyfraktometru rentgenowskiego wyposażonego w lampę miedzianą. Wynik pomiarów (XRD) wykazał, że material w stanie po zestaleniu i obróbce termicznej jest amorficzny. Statyczne pętle histerezy i krzywą pierwotnego namagnesowania zmierzono za pomocą magnetometru wibracyjnego (VSM). Analizując krzywą pierwotnego namagnesowania i wykorzystując pośrednią metodę wyznaczania defektów strukturalnych zgodnie z teorią H. Kronmüllera wyznaczono jakość i ilość tych defektów w próbce w stanie po zestaleniu i po izotermicznym wygrzewaniu. Badania te wykazały że proces wygrzewania istotnie wypływa na zmiany zdefektowania struktury amorficznej w wyniku czego zachodzą zmiany parametrów magnetycznych takich jak magnetyzacja nasycenia μ0Ms i pole koercji Hc.

11

Defects in the structure of Fe60Co10W2Me2Y8B18 amorphous metallic glasses, where Me=(Mo,Nb)

Garus S., Garus J., Nabiałek M., Błoch K., Gruszka K., Szota M.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 61, nr 2

175--180

EN

Purpose: The paper presents results of the effect of structural defects on the process of magnetization in high magnetic fields in metallic glasses based on amorphous Fe60Co10W2Me2Y8B18 (where Me=Mo, Nb) Design/methodology/approach: Bulk amorphous material samples were obtained with the method of rapid radial cooling in the copper liquid-cooled mould in a protective atmosphere of inert gas. The samples in the state after solidification were then examined using a vibrating magnetometer in the magnetic fields up to 2T. Static magnetic hysteresis loops and primary magnetization curve were recorded. Findings: Changing a small amount of the element from the group of transition metals have a significant effect on the magnetic properties of the produced alloy. Depending on the substituent also the type of defects identified in the examined materials changes. Research limitations/implications: It is advisable to conduct studies on samples with compositions close to studied in this work for better prediction of magnetic properties of materials. Practical implications: Bulk amorphous metallic glass are used in the electrical industry as cores in modern high-efficiency high-power transformers. Originality/value: W Paper presents studies on the influence of structure defects on the process of primary magnetization for amorphous Fe60Co10W2Mo2Y8B18 and Fe60Co10W2Nb2Y8B18 alloys. Alloys of given composition has not yet been tested for the influence of defects on the magnetization process.

12

Structure of the amorphous-crystalline Fe66Cu6B19Si5Nb4 alloy obtained by the melt-spinning process

Kozieł T., Latuch J., Zielińska-Lipiec A.

Archives of Metallurgy and Materials

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2013

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Vol. 58, iss. 2

601--605

EN

This paper presents structure investigations of the rapidly cooled Fe66Cu6B19Si5Nb4 alloy. A proper selection of chemical composition enabled in-situ formation of the amorphous-crystalline composite during the melt spinning process. Liquid phase separation into the Fe-rich and the Cu-rich phases was confirmed. The microstructures of alloy, melt-spun from 1723 and 1773 K, are composed of the Fe-rich amorphous matrix and Cu-rich spherical crystalline precipitates. For the higher melt-ejection temperature, no coarse precipitates could be observed. Amorphous nature of the Fe-rich matrix was confirmed by presence of a broad diffraction maximum on the X-ray diffraction patterns, a halo ring on the electron diffraction pattern as well as presence of exothermic effects, related to the crystallization of the Fe-rich amorphous matrix, in the differential scanning calorymetry. Beside presence of copper, revealing positive heat of mixing with iron, relatively large supercooled liquid region, was noticed.

PL

Praca przedstawia badania kompozytu amorficzno-krystalicznego otrzymanego w stopie Fe66Cu6B19Si5Nb4. Badania obejmowały rentgenowską analizę fazową (XRD), skaningową kalorymetrie różnicową (DSC), mikroskopię swietlną (LM), skaningową mikroskopię elektronową (SEM) i transmisyjną mikroskopię elektronową (TEM). Odpowiedni dobór składu chemicznego umożliwił uzyskanie kompozytu amorficzno-krystalicznego dzięki wykorzystaniu zjawiska podziału w stanie ciekłym w efekcie dodatniego ciepła tworzenia roztworu pomiędzy żelazem i miedzią. Mikrostruktury badanego stopu, po odlaniu z temperatury 1723 i 1773 K, składają się z amorficznej osnowy bogatej w żelazo i krystalicznych kulistych wydzieleń bogatych w miedź. Dla wyższej temperatury odlewania nie obserwowano dużych wydzieleń. Obecność fazy amorficznej została potwierdzona poprzez obecność halo na dyfrakcji elektronowej oraz efekt cieplny egzotermiczny w badaniach skaningowej kalorymetrii różnicowej, związany z krystalizacją osnowy bogatej w żelazo. Pomimo dodatku miedzi, wykazującej dodatnie ciepło tworzenia roztworu z żelazem, wyznaczony zakres cieczy przechłodzonej jest względnie duży.

13

Specific heat investigation of bulk metallic glasses

Januszka A.

Archives of Materials Science and Engineering

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2013

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Vol. 64, nr 2

144--151

EN

Purpose: The aim of the paper is measurements and analysis of specific heat (Cp) of bulk metallic glasses. The fabrication method and structure analysis were also described. Design/methodology/approach: The studies were carried out on FeCo-based glassy test pieces with the following composition: Fe36Co36B19.2Si4. Samples in form of rods were prepared by copper mould casting method. The structure was tested by X-ray diffraction method and scanning electron microscope observation (SEM). For determination of thermal properties the DTA and DSC method were used. Specific heat of amorphous samples was investigated by calorimetric method. Findings: The X-ray diffraction revealed that fabricated samples exhibit glassy structure. Broad diffraction halo could be seen for each tested sample. SEM observations show that fracture morphology is changed on the diameter of samples. Thermal analysis allows assigning liquidus temperature (Tl). On the base of DSC curves glass transition temperature (Tg) and crystallization temperature (Tx) were determinate. Specific heat investigation show insignificant changes in temperature range from 30 K to Tg. Practical implications: Bulk glassy FeCo-based alloys which are fabricated by rapidly solidifying technique are very interesting engineering materials because of its unique mechanical and magnetic properties. They could be used in many applications. Specific heat is important in solidification process. This property is significant input-data in computer simulation of solidification process. Originality/value: It is important to investigate thermal properties of bulk metallic glasses (including Cp) in order to understand mechanism of structural relaxation, glass transition and crystallization sequences.

14

The study of glass forming ability of Fe-based alloy for welding processes

Pilarczyk W.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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Vol. 52, nr 2

83--90

EN

Purpose: This paper tends to present the thermal analysis and structure of selected Fe-based bulk metallic glasses for welding processes. Design/methodology/approach: The studies were performed on Fe-Co-B-Si-Nb alloy in form of plate and rod. Master alloy ingot with compositions of Fe37.44Co34.56B19.2Si4.8Nb4 was prepared by induction melting of pure Fe, Co, B, Si and Nb elements in argon atmosphere. The investigated material was cast in form of plate with thickness 0.5 mm and rod with diameter 3 mm. The structure analysis of the studied materials in as-cast state was carried out using X-ray diffraction (XRD). The thermal properties: glass transition temperature (Tg), onset crystallization temperature (Tx) and peak crystallization temperature (Tp) of the as-cast alloys were examined by differential scanning calorimetry (DSC) and melting temperature (Tm), liquidus temperature (Tl) by differential thermal analysis (DTA) methods. The parameters of glass forming ability included reduced glass transition temperature (Trg), supercooled liquid region (ΔTx), α, β, y, δ and stability (S) were calculated. Findings: The Fe-based bulk metallic glasses in form of plate and rod with good glass forming ability were produced by die pressure casting method. The investigation methods revealed that the studied as-cast bulk metallic glasses were amorphous. These materials exhibit good glass-forming ability. The calculated GFA parameters indicated that the slightly best glass-forming ability has Fe37.44Co34.56B19.2Si4.8Nb4 alloy in form of rod. It is confirmed that these parameters could be used to determine glass forming ability of tested amorphous alloy for welding processes. Research limitations/implications: It is difficult to obtain a bulk metallic glasses in form of plate and rod with large sizes. Various empirical parameters have been proposed to specify the glass forming ability of bulk metallic glasses. Several GFA indicators have been determined by measuring the characteristic thermal parameters. A few simple criteria were calculated to explain the GFA of tested alloys. Practical implications: These obtained values of GFA parameters can suggest that studied alloys are suitable materials for further practical application at welding process. Originality/value: The success formation and investigation of the casted Fe-based bulk metallic glasses. The chemical composition of Fe37.44Co34.56B19.2Si4.8Nb4 alloy were tested first time.

15

Structure and magnetic properties of Fe56Co7Ni7B20Nb10 metallic glasses

Lesz S., Nabiałek M., Nowosielski R.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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Vol. 55, nr 2

270--274

EN

Purpose: This paper presents results of investigation of structure and magnetic properties of Fe56Co7Ni7B20Nb10 metallic glasses prepared from industrial raw materials. The investigated samples were cast in form of the ribbons. Ribbons were prepared by the single copper roller melt spinning method. The casting conditions include linear speed of copper roller: ν = 18 and ν = 20 m/s and ejection over-pressure of molten alloy: p = 0.02 MPa. Design/methodology/approach: The structure was characterized by X-ray diffraction (XRD) method, transmission electron microscope (TEM), scanning electron microscope (SEM). The magnetic properties contained, coercive force Hc, initial magnetic permeability μi and magnetic after-effects Δμ/μ measurements were determined by the coercivemeter and with the use of automatic device for measurements magnetic permeability, respectively. Magnetic hysteresis loops were measured with a vibrating sample magnetometer (VSM) under an applied field up to 2 T. Magnetic properties of saturation magnetization – Ms was determined from achieved magnetic hysteresis loops. Hysteresis loops, recorded using a computer controlled DC hysteresis loop tracer, were used to obtain hysteresis parameters. Findings: The XRD and TEM investigations revealed that the studied ribbons were amorphous. The SEM images showed that studied fractures morphology of ribbons is changing from smooth fracture inside with few veins network in surface freely solidified (shining surface). Character of fracture morphology revealed ductile character of Fe56Co7Ni7B20Nb10 ribbons with vein pattern morphology, typical for amorphous alloys. The detailed analysis of data of magnetic properties i.e. Ms. Μi and Hc allow to classify the alloy in as quenched state as a soft magnetic material. Research limitations/implications: The results can give more details to understand the relationship between structure and magnetic properties. Thus can be useful for practical application of these alloys. Practical implications: The Fe, Co, Ni-based metallic glasses due to their properties such as excellent magnetic properties are the most attractive and promising for the future applications as new prominent class of engineering and functional material. Thin ribbons of magnetic metallic glasses are currently used in transformer cores, in magnetic sensors, and for magnetic shielding. Higher thicknesses would be useful particularly for the latter two applications. Originality/value: The applied investigation methods are suitable to determine the changes of structure and soft magnetic properties of examined Fe56Co7Ni7B20Nb10 metallic glasses with function of sample thickness.

16

Investigation of the structure and properties of Fe-Co-B-Si-Nb bulk amorphous alloy obtained by pressure die casting method

Pilarczyk W., Nowosielski R., Babilas R., Sakiewicz P., Pilarczyk A.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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Vol. 55, nr 2

363--367

EN

Purpose: The main aim of this paper is investigation of the microstructure and thermal properties of selected Fe-Co-B-Si-Nb bulk amorphous alloy. Design/methodology/approach: The studies were performed on Fe-Co-B-Si-Nb alloy in form of rods with diameter of ø0=1.5 and ø=2 mm. Master alloy ingot with compositions of Fe37.44Co34.56B19.2Si4.8Nb4 was prepared by induction melting of pure Fe, Co, B, Si and Nb elements in argon atmosphere. The structure analysis of the studied materials in as-cast state was carried out using X-ray diffraction (XRD). The thermal properties: glass transition temperature (Tg), onset crystallization temperature (Tx) and peak crystallization temperature (Tp) of the as-cast alloys were examined by differential scanning calorimetry (DSC) method. The microscopic observation of the fracture morphology of studied amorphous materials in rods form with different diameter was carried out by means of scanning electron microscope (SEM), within different magnification. Findings: The Fe-based bulk metallic glasses in form of rod were successfully produced by die pressure casting method. The investigation revealed that the studied rods are amorphous. These materials exhibit good glass-forming ability. These tested rods with diameter of 1.5 and 2 mm exhibit similar characteristic temperatures (Tg, Tx, Tp). The exothermic peaks describing crystallization process of studied bulk metallic glasses are observed Morphology of cross section rods is changing having contact with copper mould during casting from smooth fracture inside rod to fine narrow dense veins pattern near to rod surface. These rods have smooth surface and metallic luster. The presented fractures are characteristic for metallic glasses. Practical implications: The success of production of studied Fe-based bulk metallic glasses is important for future practical application of those materials as elements of magnetic circuits, sensors and precise current transformers. Originality/value: The success formation and investigation of the casted Fe-based bulk metallic glasses. The chemical composition of Fe37.44Co34.56B19.2Si4.8Nb4 alloy in form of rod were tested first time.

17

Structure, thermal and magnetic properties of (Fe72B20Si4Nb4)100-xYx(x=0.3) metallic glasses

Babilas R., Griner S., Sakiewicz P., Nowosielski R.

Journal of Achievements in Materials and Manufacturing Engineering

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2011

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Vol. 44, nr 2

140--147

EN

Purpose The work presents structure characterization, thermal and soft magnetic properties analysis of selected Fe-based metallic glasses in as-cast state and after crystallization process. Design/methodology/approach: The studies were performed on Fe72B20Si4Nb4 and Fe70B19Si4Nb4Y3 metallic glasses in form of ribbon. The amorphous structure of tested samples was examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM) methods. The crystallization behaviour of the studied alloys was examined by differential thermal analysis (DTA) and differential scanning calorimetry (DSC). The soft magnetic properties examination of tested materials contained initial magnetic permeability and magnetic permeability relaxation measurements. Findings: The XRD and TEM investigations confirmed that the studied alloys Fe72B20Si4Nb4 and Fe70B19Si4Nb4Y3 were amorphous in as-cast state. The liquidus temperature assumed as the end temperature of the melting isotherm on the DTA reached a value of 1550 K and 1560 K for Fe72B20Si4Nb4 and Fe70B19Si4Nb4Y3 alloy, adequately. The analysis of crystallization process indicated that onset and peak crystallization temperature increased with increasing of heating rate at DSC measurements. The samples of Fe72B20Si4Nb4 alloy presented two stage crystallization process. The initial magnetic permeability of examined samples increased together with the increase of annealing temperature and reached a distinct maximum at 773 K for Fe72B20Si4Nb4 and at 723 K for Fe70B19Si4Nb4Y3 alloy. Practical implications The increasing of annealing temperature significantly improved soft magnetic properties of examined alloys by increase the initial magnetic permeability. Originality/value: The applied investigation methods are suitable to determine the changes of structure and selected properties between studied alloys, especially in aspect of the soft magnetic properties improvement after annealing process.

18

Structure studies of Fe-based metallic glasses by Mössbauer spectroscopy method

Babilas R., Kądziołka-Gaweł M., Nowosielski R.

Journal of Achievements in Materials and Manufacturing Engineering

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2011

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Vol. 45, nr 1

7--12

EN

Received 10.01.2011; published in revised form 01.03.2011 Purpose: The paper presents a structure characterization of selected Fe-based metallic glass in as-cast state. Design/methodology/approach: The studies were performed on Fe72B20Si4Nb4 metallic glass in form of ribbons. The amorphous structure of tested samples was examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM) methods. Mössbauer spectroscopy method was applied to comparison of structure in studied amorphous samples with different thickness (cooling rates). Findings: The XRD, TEM and Mössbauer spectroscopy investigations revealed that the studied alloy in as-cast state was amorphous. Comparison of diffraction patterns of studied samples with different thickness showed the slightly narrowing of diffraction lines. The TEM observations also revealed a changing of image contrast of glassy ribbons with increase of sample thickness. The Mössbauer spectra presented broadened six line patterns characteristic to the structural disorder of amorphous ferromagnetic materials. The hyperfine magnetic field distributions for studied sample thickness indicated the existence components corresponding to the regions with different iron concentration (an iron-rich and an iron-poor surroundings). Practical implications: The Mössbauer spectroscopy is very useful method in studying the structural environment of Fe atoms on a nearest-neighbor length scale allowing the analysis of iron-containing phases. Originality/value: The obtained examination results confirm the utility of investigation methods in analysis of microstructure in function of sample thickness.

19

The microstructure of rapidly quenched Fe-Cu-based alloy with a liquid miscibility gap

Kozieł T., Kędzierski Z., Zielińska-Lipiec A., Latuch J.

Inżynieria Materiałowa

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2010

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Vol. 31, nr 3

470-473

EN

The microstructures of rapidly quenched Fe37Cu25Si13B9Al8Ni6Y2 alloy are presented. Rapid cooling (melt spinning technique) of the melt enabled in situ formation of amorphous-crystalline composites. Four different melt ejection temperatures, in the range from 1330 to 1520°C, were applied in order to study effect of initial melt temperature on the microstructure of resultant ribbons. Coarse segregated, elongated areas were observed for low melt ejection temperature, indicating cooling from the miscibility gap region. Increase of the melt ejection temperature up to homogeneous melt region, brought about formation of spherical particles distributed within a homogeneous matrix. Detailed investigations, including X-ray diffraction, differential scanning calorymetry, scanning and transmission electron microscopy, proved amorphous nature of the Fe-rich matrix and crystalline structure of the Cu-rich precipitates. Moreover, presence of the secondary formed spherical particles within primarily precipitated the Cu-rich spheres, was observed.

PL

W pracy przedstawiono mikrostrukturę stopu Fe37Cu25Si13B9Al8Ni6Y2 po szybkim chłodzeniu. Wykazano, że gwałtowne chłodzenie fazy ciekłej (metoda melt spinning) umożliwia wytworzenie in situ kompozytów amorficzno-krystalicznych. W celu określenia wpływu temperatury odlewania stopów na mikrostrukturę taśm, odlewano je z czterech rożnych temperatur z zakresu 1330÷1520°C. Zaobserwowano, że mikrostruktura taśm odlanych z niskiej temperatury charakteryzuje się obecnością dużych, wydłużonych obszarów, co wskazuje, że w trakcie nagrzewania osiągnięto temperaturę z zakresu niemieszalności cieczy. Podwyższenie temperatury odlewania do zakresu jednorodnej cieczy spowodowało, iż w trakcie chłodzenia przez zakres niemieszalności, jedna z faz ciekłych wydziela się w postaci kulistych wydzieleń. Szczegółowe badania, obejmujące rentgenowską analizę fazową, skaningową kalorymetrię różnicową, mikroskopię skaningową i transmisyjną, dowiodły amorficzny charakter osnowy bogatej w Fe oraz krystaliczną strukturę wydzieleń bogatych w Cu. Ponadto w pierwotnie utworzonych cząstkach bogatych w Cu zaobserwowano wtórne kuliste wydzielenia.

20

Nanocrystalization of NiNb(ZrTi)Al metallic glasses

Czeppe T.

Inżynieria Materiałowa

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2010

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Vol. 31, nr 3

673-676

EN

The melt spun ribbons of composition Ni58Nbx(ZrTi)1-xAly (x = 5, 10, 20 i 25, y = 3, 7% at.) were investigated. It was found that the crystallization of the amorphous phase proceeded due to two deferent mechanisms in case of the alloys containing less and more than 15 at. % Nb. In both cases different compositions of crystallizing phases and kinetics parameters were found. In case of alloys containing less than 15 at. % Nb, cubic NiTi(Zr) phase crystallized rapidly and completely replaced amorphous phase. In alloys with higher Nb content, a smaller volume, up to 50% of the amorphous phase crystallized in a much slower process, also the resulting phase composition was much complicated. The transformation rates and activation energies determined with use of the Matusita method, invented for the oxide glasses kinetics determination and assuming activation energy evolution during the process are discussed. The Matusita method revealed limited usefulness as it could be applied only to the slower crystallization process.

PL

Badano taśmy amorficzne o składzie Ni58Nbx(ZrTi)1-xAly (x = 5, 10, 20 i 25, y = 3, 7% at.), otrzymane metodą szybkiej krystalizacji na wirującym dysku. Stwierdzono, że faza amorficzna krystalizuje inaczej w przypadku stopów o zawartości Nb mniejszej i większej od 15% at. Stwierdzono inny skład fazowy po krystalizacji i inne parametry kinetyczne. W przypadku szkieł o zawartości Nb mniejszej niż 15% at. gwałtownie krystalizuje faza regularna NiTi(Zr) i całkowicie zastępuje fazę amorficzną. W stopach o wyższej zawartości Nb krystalizacja obejmuje do 50% fazy amorficznej, proces jest znacznie wolniejszy, a skład fazowy po krystalizacji bardziej złożony. Określono i przedyskutowano szybkość przemiany, a także energię aktywacji krystalizacji, w tym ostatnim przypadku stosując równanie Matusity, wynalezione do opisu kinetyki krystalizacji szkieł tlenkowych i zakładające ewolucję energii aktywacji w trakcie procesu. Użyteczność tej metody okazała się ograniczona do wolniejszego procesu krystalizacji.