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1

Geopolymer fly ash composites modified with cotton fibre

Kozub Barbara, Pławecka K., Figiela B., Korniejenko K.

Archives of Materials Science and Engineering

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2023

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Vol. 121, nr 2

60--70

EN

Purpose: The work’s primary goal is to assess the influence of the cotton fibres addition and their proportion on the strength properties and thermal conductivity of foamed geopolymer composites based on fly ash. Design/methodology/approach: Fly ash from a thermal power plant was used as the foundation material to create the geopolymer composites in this study. Volcanic silica was used as an additional source of silicon. As an additive, the recycled cotton flock was used in amounts of 0.5%, 1% and 2% by weight of dry ingredients. The density, compressive, and three-point bending strength of the created geopolymers were measured. Moreover, the thermal conductivity measurements for three temperature ranges: 0–20°C, 20–40°C, and 30–50°C for all investigated geopolymers were conducted. The structure of tested materials was observed using a scanning electron microscope (SEM). Findings: It was demonstrated within the context of the study that the addition of cotton fibres to foamed fly ash-based geopolymers aids in slightly reducing their density. Cotton fibres can be used to boost the strength of the examined geopolymers; for samples with 1% cotton fibres added, compressive strength rose by around 22% and flexural strength by about 67%. Additionally, it is feasible to lower their thermal conductivity coefficient by incorporating cotton fibres into foamed fly ash-based geopolymers. Practical implications: The results obtained highlight the potential of fly ash-based geopolymer composites with the addition of cotton flocks for application as insulating materials in the building industry. Originality/value: The novelty of this work is the demonstration of the possibility of producing foamed geopolymers based on fly ash with the addition of recycled cotton fibres, with properties that make them suitable for use as building insulation materials.

2

Research on diatomite from Polish deposits and the possibilities of its use

Marczyk J., Pławecka K., Hebdowska-Krupa M., Nykiel M., Łach M.

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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Vol. 115, nr 1

5--15

EN

Purpose: Diatomite from a deposit in Jawornik Ruski (Poland) has been selected as the material for study. The paper aimeds to show the possibility of using diatomite from the Carpathian Foothills as a sorbent of petroleum substances. Design/methodology/approach: Diatomite in the delivery condition (DC) and diatomite after calcination were used for this study. The material was calcined at 600, 650, 750, 850 and 1000°C. The diatomaceous earth was then granulated. The morphology of diatomite was observed using SEM. Particle size distribution was determined by Laser Particle Analyzer, chemical composition was determined by XRF, and mineralogical composition by XRD. Specific surface area, pore volume and pore size were determined. Thermal analysis (TG, DTA) was carried out. Absorption capacity tests were performed and the effect of diatomite addition on water absorption of concrete samples was determined. Findings: Within the framework of the study, it was shown that diatomite from the Jawornik deposit could be successfully used as a sorbent for petroleum substances. The absorption capacity of calcined at 1000°C diatomaceous earth was 77%. The obtained result exceeds the effectiveness of previously used absorbents, for which the sorption level is 60-70%. This allows commercial use of diatomite from deposits in Poland. In addition, water absorption tests have shown that diatomaceous earth can successfully replace cement used in concrete productione. The most favourablee effect on the reduction of water absorption is the addition of diatomite in the amount of 10%. Practical implications: The properties of diatomaceous earth from the Jawornik Ruski deposit indicate its high potential for use in the synthesis of geopolymers, which is important not only from an economic but also from an ecological point of view. Originality/value: The novelty of this work is the demonstration of the possibility of using diatomite as a sorbent of petroleum substances with high efficiency, exceeding the previously used sorbents.

3

Hybrid ZnO/ZnO-NPs nanofibres fabricated via electrospinning

Matysiak W., Zaborowska M.

Journal of Achievements in Materials and Manufacturing Engineering

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2019

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Vol. 94, nr 1-2

5--12

EN

Purpose: Due to the growing interest and multitude of possible applications, zinc oxide nanowires, including those doped with ZnO nanoparticles, can became, alongside carbon nanotubes, a very desirable material which use is predicted in the construction of nanogenerators, dye sensitized solar cells, optoelectronics or ultrasensitive gas detectors. Design/methodology/approach: The electrospinning process allows for low-cost and scalable production of fibrous mats with diameters from a few to several hundred nanometers. What is more, electrospinning method has gained popularity also due to its versatility, now it is possible to produce fibres from almost every known polymer and the simplicity and lack of any additional functionalization of the obtained nanomaterials. The application of the calcination process to remove the polymer matrix from the obtained nanofibres results in the creation of ceramic nanofibres. Findings: Among the existing methods for the production of ceramic nanostructures, including the hydrothermal, physical and chemical vapour deposition methods, nanolithography or molecular self-assembly, the electrospinning process creates the possibility of fabricating one-dimensional nanostructures with unprecedented properties, good quality, no additional functionalization and purification. Research limitations/implications: Due to ongoing research on the potential applications of zinc oxide nanostructures, including photovoltaics, sensorics and electronics, the most predictable behaviour and properties of ZnO nanowires characterize those nanomaterials that exhibit a periodic structure of the crystal lattice. Considering the optimization of the parameters of the method of producing ceramic zinc oxide nanowires doped with crystalline ZnO nanoparticles, it is worth analysing the thermal treatment parameters of nanofibres. Practical implications: Although amorphous structure, hybrid ZnO nanofibres could be used as humidity sensors with much higher sensing properties than crystalline ZnO nanostructures. Originality/value: Low-cost, scalable production of ceramic nanofibres for most technical applications.

4

Amorphous materials in the production of new implants

Kiljan A., Liptakova T.

Production Engineering Archives

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2018

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Vol. 18

50--53

EN

Amorphous materials based on magnesium are new materials for potential biomedical application, especially for new implants, as they bear resemblance to titanium implants. Mg66Zn30Ca4 alloy has specific properties, especially mechanical and corrosive, therefore, it has biomedical application as its properties are better than that of other materials. The following paper describes amorphous alloy based on magnesium, properties and shows how to produce amorphous samples of Mg66Zn30Ca4.

5

Optymalizacja konstrukcji transformatorów w aplikacjach elektromobilnych

Łukiewski M., Łukiewska A.

Napędy i Sterowanie

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2018

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R. 20, nr 12

106--109

PL

W artykule omówiono wybrane zagadnienia optymalizacyjne związane z budową transformatorów pracujących w przetwornicach pojazdów elektromobilnych. Porównano wyniki symulacji wpływu materiału magnetycznego rdzenia na straty i wymiary gabarytowe transformatora. Przedstawiono również optymalizację konstrukcji transformatora w celu zwiększenia skuteczności wymuszonego chłodzenia. Parametry symulowano, wykorzystując oprogramowanie projektowe firmy RALE Engineering GmbH.

EN

In this article selected optimizing issues related to the construction of the transformers worked in static converters of electro-mobile vehicles were discussed. The simulation of the effect of core magnetic material on the losses and transformer sizes have been compared. Moreover, the increase of effected – cooling due to solution of transformer construction were performed. The parameters were simulated using design software by RALE Engineering GmbH.

6

Optymalizacja konstrukcji transformatorów w aplikacjach elektromobilnych

Łukiewski M., Łukiewska A.

Maszyny Elektryczne : zeszyty problemowe

|

2018

|

Nr 3 (119)

185--188

PL

W artykule omówiono wybrane zagadnienia optymalizacyjne związane z budową transformatorów pracujących w przetwornicach pojazdów elektromobilnych. Porównano wyniki symulacji wpływu materiału magnetycznego rdzenia na straty i wymiary gabarytowe transformatora. Przedstawiono również optymalizację konstrukcji transformatora w celu zwiększenia skuteczności wymuszonego chłodzenia. Parametry symulowano wykorzystując oprogramowanie projektowe firmy RALE Engineering GmbH.

EN

In this article selected optimizing issues related to the construction of the transformers worked in static converters of electro-mobile vehicles were discussed. The simulation of the effect of core magnetic material on the losses and transformer sizes have been compared. Moreover, the increase of effected – cooling due to solution of transformer construction were performed. The parameters were simulated using designsoftware by RALE Engineering GmbH.

7

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.

8

Effect of structural relaxations within the amorphous structure on the magnetic properties of amorphous tapes from FeCoB family

Szota M.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 1

217--222

EN

The paper presents the research results for the Fe78Co2Si9B11 amorphous alloy, and after the process of annealing resulting only in the relaxation of the material. The structure relaxations occurring in the volume of test samples lead to the changes in their magnetic and mechanic properties. Therefore the studies on the effect of the structure defects on the properties of these type of materials are important. Understanding the processes occurring during the magnetizing of amorphous alloys can be helpful in the design of modern functional materials for special purposes. The main purpose of this elaboration was to determine the effect of the amorphous structure defects in the state after solidification and after heat treatment on the changes in the magnetizing process and in such parameters as the saturation magnetization and the coercivity field.

9

Measurement of the Indentation Modulus and the Local Internal Friction in Amorphous SiO2 Using Atomic Force Acoustic Microscopy

Zhang B., Wagner H., Büchsenschütz-Göbeler M., Luo Y., Küchemann S., Arnold W., Samwer K.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 1

9--12

EN

For the past two decades, atomic force acoustic microscopy (AFAM), an advanced scanning probe microscopy technique, has played a promising role in materials characterization with a good lateral resolution at micro/nano dimensions. AFAM is based on inducing out-of-plane vibrations in the specimen, which are generated by an ultrasonic transducer. The vibrations are sensed by the AFM cantilever when its tip is in contact with the material under test. From the cantilver’s contactresonance spectra, one determines the real and the imaginary part of the contact stiffness k*, and then from these two quantities the local indentation modulus M' and the local damping factor Qloc-1 can be obtained with a spatial resolution of less than 10 nm. Here, we present measured data of M' and of Qloc-1 for the insulating amorphous material, a-SiO2. The amorphous SiO2 layer was prepared on a crystalline Si wafer by means of thermal oxidation. There is a spatial distribution of the indentation modulus M' and of the internal friction Qloc-1. This is a consequence of the potential energy landscape for amorphous materials.

10

Variation of temperature field created at pulsed laser irradiation of amorphous Fe73.7Si15.5B7.4Nb2.4Cu1.0 alloy

Nykyruy Yu.S., Mudry S. I.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2015

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Vol. 19, No 1

75--82

EN

The temperature in the laser irradiation area of an amorphous iron-based ribbon was calculated. As a result of the calculation a spatial temperature distribution and its time dependence were structured which allowed reproducing the geometric and structural characteristics of exposed areas. Simultaneously, an irradiated amorphous alloy was investigated by scanning electron microscopy which allowed determining the geometric and structural characteristics of these areas experimentally and obtaining their dependencies on the laser pulse parameters. The results of theoretical calculations were compared with the experimental data.

11

Effects of Co, Ni, and Cr addition on microstructure and magnetic properties of amorphous and nanocrystalline Fe86−xMxZr7Nb2Cu1B4 (M = Co, Ni, CoCr, and Cr, x = 0 or 6) alloys

Łukiewska A., Świerczek J., Hasiak M., Olszewski J., Zbroszczyk J., Gębara P., Ciurzyńska W.

Nukleonika

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2015

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Vol. 60, No. 1

103--108

EN

Mössbauer spectra and thermomagnetic curves for the Fe86-xMxZr7Nb2Cu1B4 (M = Co, Ni, CoCr, and Cr, x = 0 or 6) alloys in the as-quenched state and after the accumulative annealing in the temperature range 600–800 K for 10 min are investigated. The parent Fe86Zr7Nb2Cu1B4 amorphous alloy is paramagnetic at room temperature, and substitution of 6 at.% of Fe by Co, Ni, and CoCr changes the magnetic structure – the alloys become ferromagnetic, whereas replacing 6 at.% of Fe with Cr preserves the paramagnetic state. After the heat treatment at 600 K, the decrease of the average hyperfi ne fi eld induction, as compared to the as-quenched state, is observed due to the invar effect. After this annealing, the Curie temperature for all investigated alloys decreases. The accumulative annealing up to 800 K leads to the partial crystallization; α-Fe or α-FeCo grains with diameters in the range of 12–30 nm in the residual amorphous matrix appear.

12

Cu47Ti34Zr11Ni8 amorphous alloy fabricated by the pressure die casting method

Nowosielski R., Guwer A., Gawlas-Mucha A.

Journal of Achievements in Materials and Manufacturing Engineering

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2015

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Vol. 70, nr 1

5--12

EN

Purpose: The aim of present work is characterization of the pressure die casting, fabrication and testing of structure and properties Cu47Ti34Zr11Ni8 ingot and amorphous and crystalline alloys prepared in the form of rods. Design/methodology/approach: The preliminary ingot was prepared by using the method of arc melting. Rods were fabricated by the pressure die casting method. The melting point and liquidus temperatures of the ingot were determinated in the thermal analysis DTA. Analysis of the microstructure of a pre-alloy was carried out by using the EDS method. X-ray diffraction was used to study structure of fabricated ingot and rods. Hardness was measured by using the Vickers method and compression tests were also performed. Findings: Modernization of the pressure die casting station in the form of housing, which was made from the plexiglass, allowed to keep a protective atmosphere during casting, after that alloys did not oxidate. The X-ray diffraction investigations were indicated that the examined quaternary rods with 2 mm and 3 mm diameters had amorphous structure. The rod with diameter of 4 mm had crystalline structure. The phases occur in ingot and crystalline rods were identified by using X-ray card. Rod about 4mm diameter demonstrated the highest hardness. The rod with diameter of 3 mm demonstrated the highest compressive strength - 1798 MPa. Research limitations/implications: In the future, the research of mechanical properties of Cu47Ti34Zr11Ni8 amorphous rod will be performed. Moreover, further attempts of a fabrication of the Cu47Ti34Zr11Ni8 amorphous rod about diameter higher than 3 mm, will be prepared. Practical implications: A manufactured housing enables the production of bulk metallic glasses about different chemical compositions, by preventing possible oxidations of elements. Originality/value: Modernization of position for the pressure die casting into copper mould. A comparison of properties of Cu47Ti34Zr11Ni8 amorphous and crystalline rods.

13

Amorphization and liquid state separation in Ni80-2xCuxFexP20 alloys

Ziewiec K., Prusik K., Różycka M.

Metallurgy and Foundry Engineering

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2014

|

Vol. 40 no. 1

45-54

EN

The aim of the work is to study the ability and potential of glass formation in Ni-Fe-Cu-P alloys. A series of alloys were produced in arc furnace (i.e. Ni70Fe5Cu5P20, Ni60Fe10Cu10P20, Ni50Fe15Cu15P20, Ni40Fe20Cu20P20, Ni30Fe25Cu25P20, Ni20Fe30Cu30P20). The primary microstructure of the ingots was studied. The ribbons in as-melt-spun state were characterized by X-ray diffraction (XRD). The Ni70Fe5Cu5P2, Ni60Fe10Cu10P20 melt-spun alloys were found to be amorphous. For higher copper and iron concentrations a crystalline structure was obtained after melt spinning. This correlated with the tendency for the formation of the Fe-based phases enriched in P and Cu-based poorly alloyed phases which resulted in the formation of crystalline microstructure in melt-spun ribbons. For higher concentration of Fe and Cu, microstructures of the alloys contained constituents resultant from a tendency for separation in the liquid state. It is observed that the formation of the crystal line melt-spun ribbons is caused by the attraction of phosphorus by iron and the formation of copper-based fcc phase.

PL

Celem pracy było zbadanie podatności na zeszklenie oraz możliwości wytworzenia struktury szklistej w stopach wieloskładnikowych Ni-Fe-Cu-P. W piecu łukowym wytworzono serię stopów (tzn.: Ni70Fe5Cu5P20, Ni60Fe10Cu10P20, Ni50Fe15Cu15P20, Ni40Fe20Cu20P20, Ni30Fe25Cu25P20, Ni20Fe30Cu30P20). Badano strukturę pierwotną wlewków. Taśmy w stanie po odlewaniu na wirujący bęben badano za pomocą dyfrakcji rentgenowskiej. Stwierdzono, że stopy Ni70Fe5Cu5P20, Ni60Fe10Cu10P20 odlewane na wirujący bęben były amorficzne. Dla stopów o wyższych zawartościach miedzi i żelaza po odlewaniu na wirujący walec otrzymano strukturę krystaliczną. Fakt ten można powiązać z tendencją do tworzenia faz na osnowie żelaza wzbogaconych w fosfor oraz zubożonych w pozostałe składniki stopowe faz na osnowie miedzi,które przyczyniły się do tworzenia w odlewanych taśmach mikrostruktury krystalicznej. Dla wyższych zawartości żelaza i miedzi, mikrostruktury stopów zawierały składniki fazowe powstające w efekcie tendencji stopów do podziału fazowego w stanie ciekłym. Zaobserwowano, że tworze nie krystalicznych taśm jest spowodowane przez przyciąganie fosforu przez żelazo oraz tworzenie bogatej w miedź fazy o strukturze regularnej ściennie centrowanej.

14

Heterogeneity of mechanical properties and fractures of Co-based metallic glass in a low-temperature thermal activation process

Griner S., Spilka M., Kania A.

Journal of Achievements in Materials and Manufacturing Engineering

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2014

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Vol. 66, nr 2

53--60

EN

Purpose: The paper presents the changes of mechanical properties and the fractures of Co70.5Fe2.5Mn2Mo1Si9B15 metallic glass ribbons after a low-temperature activation process. Design/methodology/approach: The studied alloy was fabricated by continuous casting of the alloy stream on a turning wheel. The plastic properties were determined using the bend test. The investigations of unit cracking energy using the “tearing” test on the testing machine were carried out. The structure testing in transmission electron microscope and the static tensile test on the Instron testing machine were also carried out. Findings: The studies for 5 samples and for 2 ribbon sides were carried out. The highest plasticity occurred after annealing at 200°C for 1 h. The differences of mechanical properties in a function of a cross section of the ribbon were also presented. Practical implications: Despite the occurrence of heterogeneity of properties on the thickness of metallic glass ribbon the essential meaning have the averaging properties of a product which decided about possibility of practical application. Originality/value: In the article there was found that studied samples obtain different plasticity and different value of the yield point in the different bending methods.

15

Effect of tungsten content on glass forming ability and microhardness of Ni-Cr-B-W metallic glasses

Hitit A., Öztürk P., Şahin H., Aşgın A.M.

Journal of Achievements in Materials and Manufacturing Engineering

|

2014

|

Vol. 62, nr 1

5--9

EN

Purpose: The thermal and mechanical properties of Ni-Cr-B-W alloys as a function of tungsten content were studied. Design/methodology/approach: The studies were performed on (Ni49.7Cr14.7B35.6)100-xWx(x:15-40) metallic glass in the form of foils, which have thickness of 20 and 100 μm. Structures of samples wer examined by X-ray diffraction (XRD). Thermal stabilities of the amorphous samples were measured using differential scanning calorimetry (DSC). Microhardness of the amorphous samples were determined by Vicker’s hardness tester. Findings: The XRD investigations revealed that samples of the alloys which have the thickness of 20 μm were amorphous. However, 100 μm samples of the alloys were not amorphous, but contained crystalline phases. Increasing the tungsten addition improved the glass transition and crystallization temperatures of the alloys. Also, microhardness of the alloys improved with tungsten addition. Practical implications: Thermal and mechanical properties of the alloys investigated depend on their tungsten content. Originality/value: This is the first study on Ni-Cr-B-W metallic glass system. Also, because of the production method used, all of the alloys were obtained as amorphous regardless of their composition, so their thermal and mechanical properties could be determined.

16

The production attempt of Fe-Nb-B-Zr and Fe-Nb-B-Y system alloys by die pressure casting method

Pilarczyk W., Kucharczyk M.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 61, nr 2

222-228

EN

Purpose: The purpose of this article was to investigate the possibility of the production of Fe-Nb-B bulk metallic alloys with additions of yttrium and zirconium elements. Furthermore, this paper tends to present the structure and selected properties of obtained alloys. In this article the influence of an argon atmosphere on casting process was observed too. Design/methodology/approach: The production attempts were performed on Fe-Nb-B-Zr and Fe-Nb-B-Y system alloys in form of a plate. Master alloy ingots with compositions of Fe72B22Y4Nb2 and Fe71(Nb0.8Zr0.2)6B23 were prepared by induction melting of pure Fe, Nb, B, Y and Fe, Nb, B, Zr elements in an argon atmosphere. The ingots have been crushed and then the investigated material was cast with and without a protective atmosphere. The investigated materials were cast in form of a plate with thickness of 1 mm. The structure analysis of the studied materials in as-cast state was carried out using X-ray diffraction (XRD) and microscopic observation. The thermal properties of the alloys were examined by DSC methods. The measurments of the hardness were performed with the Vickers method. Findings: The Fe-Nb-B-Y and Fe-Nb-B-Zr system alloys in form of a plate were produced by die pressure casting method. The investigation methods revealed that the studied as-cast alloys were crystalline. The structure of the obtained plates is rather fine-grained and there were not found any impurities and undesirable phases inside the materials. The results of calorimetric curves confirm that all tested samples are crystalline. Practical implications: To extend the potential applications of the Fe-based BMGs, amorphous alloys with larger critical sizes and better processability are required. The Fe-Nb-B-Zr and Fe-Nb-B-Y bulk metallic glasses obtained by die pressure casting method can be used for production of telecommunications devices, sensors or low-energy transformers. These materials exhibit excellent mechanical and soft magnetic properties. Originality/value: An overall presentation of an influence of the yttrium and zirconium additions on the attempt of forming Fe72B22Y4Nb2 and Fe71(Nb0.8Zr0.2)6B23 alloys. The chemical composition of these alloys was tested in our laboratory for the first time.

17

The amorphous structure of Fe72B20Si4Nb4 metallic glasses in the form of rods and rings

Babilas R., Nowosielski R., Czeppe T.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 61, nr 2

150--155

EN

Purpose: The thermal and magnetic properties of Fe-based bulk amorphous materials in as-cast state in the form of rods and rings were studied. Design/methodology/approach: The studies were performed on Fe72B20Si4Nb4 metallic glass in the form of rods and rings. The amorphous structure of tested samples was examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods. The thermal stability of the glassy samples was measured using differential scanning calorimetry (DSC). The soft magnetic properties examination of tested material contained coercive force and magnetic permeability relaxation measurements. The crystallization temperature (Tp), supercooled liquid region (ΔTx), coercive force (Hc) and magnetic permeability relaxation (Δμ/μ) versus sample thickness of studied glassy samples were also examined. Findings: The X-ray diffraction and calorimetric investigations revealed that the studied Fe72B20Si4Nb4 bulk metallic glasses were amorphous. However, the differences of glass transition temperature and crystallization temperature between samples with selected thickness are probably caused by different amorphous structures. The changing of glass-forming ability and magnetic properties obtained for samples with different shape and thickness is a result of the non-homogenous amorphous structure of tested metallic glasses. The different states of amorphous phase could be caused by the free volume concentrations formed by different cooling rates in casting process. Practical implications: The soft magnetic properties of studied metallic glasses can be formed by different sample thickness which are strictly linked with different states of amorphous structure. Originality/value: The applied methods of materials investigations are suitable to determine the changes of structure and selected properties of studied samples cast in different forms and dimensions, especially in aspect of the soft magnetic properties improvement.

18

Fabrication of ternary Ca-Mg-Zn bulk metallic glasses

Nowosielski R., Borowski A., Guwer A., Babilas R.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 56, nr 2

67--74

EN

Purpose: The paper describes the preparation, structure and thermal properties of ternary Ca-Mg-Zn bulk metallic glass in form of as-cast rods. Design/methodology/approach: The investigations on the ternary Ca-Mg-Zn glassy rods were conducted by using X-ray diffraction (XRD), scanning electron microscopy (SEM) which energy dispersive X-ray analysis (EDS). Findings: The X-ray diffraction investigations have revealed that the studied as-cast rod was amorphous. The fractures of studied alloy could be classified as mixed fracture with indicated “river” and “smooth” fractures. Both type of the fracture surfaces consist of weakly formed “river” and “shell” patterns and “smooth” regions. The “river” patterns are characteristic for metallic glassy alloys. Practical implications: The studied Ca-based bulk metallic glasses is a relatively new group of material. Ca-based bulk metallic glasses are applied for many applications in different elements. Ca-based bulk metallic glasses have many unique properties such as low density (~2.0 g/cm³), low Youn g’s modulus ( ~20 to 30 GPa). The elastic modulus of Ca-b ased BMGs is comparable to that of hum an bone s, and Ca, Mg, and Zn are biocompatible. These features make the Ca-Mg-Zn–based alloys attractive for use in biomedical applications. Originality/value: Fabrication of amorphous alloy in the form of rod ternary Ca-Mg-Zn alloy by pressure die casting method.

19

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

|

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.

20

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.