Paper presents methodology of generation of the uniform, compressive or tensile stresses in ring-shaped amorphous alloys core. In this study we use the set of special nonmagnetic, cylindrical backings. These backings enabled the core to be wound as well as create the possibility of generation of uniform compressive and tensile stresses. Using presented methodology the magnetoelastic characteristics were experimentally determined for Fe40Ni38Mo4B18 Metglas 2826 MB amorphous alloy. Knowledge about these properties is important for users of inductive components with amorphous alloys cores due to the fact, that changes of flux density due to magnetoelastic effect exceed 40%.

Detailed studies on the effects of pulsed laser interference heating on surface characteristics and subsurface microstructure of amorphous Fe80Si11B9 alloy are reported. Laser interference heating, with relatively low pulsed laser energy (90 and 120 mJ), but with a variable number (from 50-500) of consecutive laser pulses permitted to get energy accumulation in heated areas. Such treatment allowed to form two- Dimensional micro-islands of laser-affected material periodically distributed in amorphous matrix. The crystallization process of amorphous FeSiB ribbons was studied by means of scanning and transmission electron microscopy. Detailed microstructural examination showed that the use of laser beam, resulted in development of nanostructure in the heated areas of the amorphous ribbon. The generation of nanocrystalline seed islands created by pulsed laser interference was observed. This key result may evidently give new knowledge concerning the differences in microstructure formed during the conventional and lased induced crystallization the amorphous alloys. Further experiments are needed to clarify the effect of pulsed laser interference crystallization on magnetic properties of these alloys.

The present study, aims to investigate the effect of minor Zr and Nb alloying on soft magnetic and electrical properties of Fe86(ZrxNb1-x)7B6Cu1 (x = 1, 0.75, 0.5, 0.25) alloys. The investigated alloys were prepared through the melt spinning process. Within the examined compositional range (Nb up to 5.25at%, respectively), the soft magnetic properties and electrical resistivity of the alloys continuously increase with increasing Nb content. However increasing the Nb content further decreases such properties. We could confirm the influence of ratio of Zr and Nb on grain growth and crystallization fraction during crystallization by using the soft magnetic properties and electrical properties.

The amorphous Mg-based alloys may be used as metallic biomaterials for resorbable orthopedic implants. The Mg-Zn-Ca metallic glasses demonstrate variable in time degradation rate in simulated body fluid. In this work the Mg₆₆Zn₃₀Ca₄ alloy was chosen as a substrate for coatings. This paper reports on the surface modification of a Mg₆₆Zn₃₀Ca₄ metallic glass by plasma electrolytic oxidation (PEO). The structure characterization of uncoated Mg₆₆Zn₃₀Ca₄ alloy was performed by using TEMand XRD method. The immersion tests of coated and uncoated Mg₆₆Zn₃₀Ca₄ alloy were carried out in Ringer’s solutionat 37°C. The volume of released hydrogen by immersion tests was determined. The coatings structure and chemical composition after immersion tests by SEM/EDS were studied. Based on SEM images of surface structure samples, immersion tests results and hydrogen evolution measurement was proposed the course of corrosion process in Ringer’s solution for Mg-based metallic glasses with PEO coating. Results of immersion tests in Ringer’s solution allowed to determine the amount of evolved hydrogen in a function of time for Mg₆₆Zn₃₀Ca₄ metallic glass and sample with PEO coating. In comparison to the non-coated Mg₆₆Zn₃₀Ca₄ alloy, the sample with PEO layer showed a significantly decreased hydrogen evolution volume.

Plant viruses create many changes in the morphology of the plant cell once the infection process has begun. This paper describes and compares the ultrastructural changes induced in maize cells by two isolates of Maize dwarfmosaic virus (MDMV), Spanish (MDMV-Sp) and Polish (MDMV-P), and one isolate of Sugarcane mosaic virus (SCMV) at 10 and 42 days post-inoculation: the concentration and arrangement of virus particles, inclusion bodies associated with infection, and other cytological alterations. The most important difference between maize cells infected with MDMV isolates and with SCMV-P1 was in the form of cytoplasmic cylindrical inclusions. In cells infected with MDMV only typical inclusions such as pinwheels and scrolls were observed, but laminar aggregates were also present in SCMV-infected cells. No virus particles were found in plant cell organelles. Specific virion arrangements occurred in cells infected with MDMV-Sp and SCMV. The most interesting new finding was of specific amorphous inclusions in the cytoplasm of MDMV-Sp-infected cells, which clearly differentiated the two MDMV isolates studied.

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.

The paper presents the novel concept of the magnetoelectric sensor constructed using the amorphous glass ribbon. Its output characteristics (voltage pattern), conditions of work and experimental results are presented. The novel construction allows for minimizing the demagnetizing field in the core of the sensor and linearization of the characteristics between the magnetic field and obtained voltage. Conducted experiments were aimed at determining the sensor operation in the presence of the constant magnetic field (HDC). The main concern of the tests was to verify the linear dependency between the HDC value and the amplitude of the output voltage. Next, the computer model representing the sensor behavior in the constant magnetic field is described. The model implements the parameter identification task based on the regression algorithms. The presented work shows that the proposed device can be used to measure the weak magnetic field and the dependency between the output signal amplitudes and the constant component in the measured magnetic field is approximately linear. This enables measurements of even weak fields.

In the present study, the corrosion behaviors of amorphous-nanocrystalline Ni50Ti50 shape memory alloy with different crystallite sizes were investigated. The Ni50Ti50 homogenized specimens were hot rolled and annealed at 950°C. Thereafter, the nanocrystalline Ni50Ti50 specimens with different crystalline sizes in the range of 40-350 nm were prepared by cold rolling and annealing at temperature range of 400 to 900oC. The corrosion resistance of Ni50Ti50 specimen with coarse grain size has significantly increased after cold rolling as a result of the formation of amorphous-nanocrystalline structure. The amorphous and nanocrystalline (with the crystallite size of about 40 nm) Ni50Ti50 samples exhibited the best corrosion resistance in the 5% HCl electrolyte with the corrosion potential and corrosion current density of about –197 mV and 2.34×10–6 A/cm2, respectively. This effect can be attributed to the higher density of crystalline defects in amorphous and nanocrystalline structures to quickly form protective films on the surface.

This study aimed to prepare Zr55Cu30Al10Ni5 bulk amorphous alloys by spark plasma sintering of raw amorphous alloy powders and investigate their microstructure and micromechanical behaviors. When the sintering temperature ( T_s) was 675K, which was lower than the glass transition temperature ( T_g) of the material, the sintered sample was almost fully amorphous but the density was lower. However, when T_s was 705K, which was higher than T_g, partial crystallization occurred, but the density was higher. The hardness of the bonding zone of the sintered sample at 675K was 5.291 GPa due to the lower density, which was lower than that at 705K, and the hardness at 705K was 8.836 GPa. The generation of thermodynamically stable intermetallic phases, the hardness, and the elastic modulus of the samples sintered above T_g were higher due to the higher density.

The study examined the impact of the angle of incidence of mechanical waves on various types of quasi one-dimensional superlattice. Binary periodic structure, quasi-periodic distribution of Thue-Morse layers and Severin’s aperiodic multilayer were used. Using the concatenation and recursive rules, the distribution of layers was determined for individual structure types for generation numbers equal to 3, 4 and 5. The structures were selected so that the thickness of the composite was the same for each type of distribution for a given generation number value. Transfer Matrix Method algorithm was used to determine reflectance. The band structure of reflectance has been demonstrated for incidence angles up to 90 degrees at mechanical wave frequencies up to 50 kHz. The existence of wide bands of high reflectance above the acoustic frequencies was demonstrated for the analyzed structures. Increasing the layer thickness caused an inhomogeneous shifts of transmission peaks towards lower frequencies.

Many variants of thin film technology are nowadays part of the photovoltaic market. The most popular are amorphous silicon, CIS (Copper Indium Selenide)/CIGS (Copper Indium Gallium Selenide)/CIGSS (Copper Indium Gallium Sulphur Selenide), and CdS/CdTe (Cadmium Sulphide/Cadmium-Telluride) cells. All mentioned types allow potentially for a flexible cell structure. Most emitter contacts are currently based on TCOs (Transparent Conductive Oxides), however, wider approach with alternative carbon nanoforms, silver nanolayers and polymer materials, called TCLs (Transparent Conductive Layers) are also in use. Authors decided to investigate influence of mechanical stresses on physical and electrical behaviour of these layers. Consequently, the aim of work is to determine the level and possible mechanisms of flexible a-Si cell parameters degradation due to a deterioration of transparent contact properties.

Particles of the Fe-Al type (less than 50 µm in diameter) were sprayed onto the 045 steel substrate by means of the detonation method. The TEM, SAED and EDX analyses revealed that the Fe-Al particles have been partially melted in the experiment of coating formation. Particle undergone melting even within about 80% of its volume. Therefore, solidification of the melted part of particles was expected. Solidification differed significantly due to a large range of chemical composition of applied particles (from 15 at.% Al up to 63 at.% Al). A single particle containing 63 at.% Al was subjected to the detailed analysis, only. The TEM / SAED techniques revealed in the solidified part of particle three sub-layers: an amorphous phase, A ε , periodically situated FeAl + Fe2Al5 phases, and a non-equilibrium phase, Nε . A hypothesis dealing with the inter-metallic phases formation in such a single particle of the nominal composition 0 N = 0.63 is presented. At first, the solid / liquid system is treated as an interconnection: substrate liquid nonmelted particle part / / . Therefore, it is suggested that the solidification occurs simultaneously in two directions: towards a substrate and towards a non-melted part of particle. The solidification mechanism is referred to the Fe-Al meta-stable phase diagram. It is shown that the melted part of particle solidifies rapidly according to the phase diagram of meta-stable equilibrium and at a significant deviation from the thermodynamic equilibrium.

In this work, the effect of heat transfer during explosive welding (EXW) and post-processing annealing on the microstructural and chemical composition changes have been thoroughly analysed using scanning and transmission electron microscopies and X-ray synchrotron radiation. Several combination of explosively welded metal compositions were studied: Ti with Al, Cu with Al, Ta or stainless steel, stainless steel with Zr or Ta and Ti with carbon steel. It was found that the melted metals exhibit a strong tendency to form brittle crystalline, nano-grained or even amorphous phases during the solidification. For all analysed metal combinations most of the phases formed in the zones of solidified melt do not appear in the equilibrium phase diagrams. Concurrently, the interfacial layers undergo severe plastic deformation forming nano-grained structures. It has been established that these heavily deformed areas can undergo dynamic recovery and recrystallization already during clad processing. This leads to the formation of new stress-free grains near the interface. In the case of low temperature and short time post processing annealing only the melted zones and severely deformed layers undergo recovery and recrystallization. However, drastic changes in the microstructure occurs at higher temperature and for longer annealing times. Applying such conditions leads to diffusion dominant processes across the interface. As a consequence continuous layers of intermetallic phases of equilibrium composition are obtained.

The aim of this work was to investigate the possibility of obtaining an amorphous/crystalline composite starting from Ni-Si- B-based powder grade 1559-40 and silver powder. The alloy was produced using arc melting of 95% wt. Ni-Si-B-based powder (1559-40) and 5% wt. Ag powder. Ingot was re-melted on a copper plate and observed while cooling using a mid-wave infra-red camera. The alloy was then melt-spun in a helium atmosphere. The microstructure of the ingot as well as the melt-spun ribbon was studied using light microscopy and scanning electron microscopy with energy dispersive spectrometry. Phase identification was performed by means of X-ray diffraction. The observations confirmed an amorphous/crystalline microstructure of the ribbon where the predominant constituent of the microstructure was an amorphous phase enriched with Ni, Si, and B, while the minor constituent was an Ag-rich crystalline phase distributed in a film along the melt-spinning direction.

Electromagnetic forces generated by the short circuit current and leakage flux in low- and high-voltage windings of distribution transformers as well as amorphous core transformers will cause the translation, destruction, and explosion of the windings. Thus, the investigation of these forces plays a significant role for researchers and manufacturers. Many authors have recently used the finite element method to analyze electromagnetic forces. In this paper, an analytic model is first developed for magnetic vector potential formulations to compute the electromagnetic forces (i.e., axial and radial forces) acting on the low- and high-voltage windings of an amorphous core transformer. The finite element technique is then presented to validate the results obtained from the analytical model. The developed model is applied to an actual problem.

The paper presents the analysis of the magnetic sensor’s applicability to the energy harvesting operations. The general scheme and technical advancement of the energy extraction from the electric vehicle (such as a tram or a train) is presented. The proposed methodology of applying the magnetic sensor to the energy harvesting is provided. The experimental scheme for the sensor characteristics and measurement results is discussed. Conclusions and future prospects regarding the practical implementation of the energy harvesting system are provided.

Through partially replacing Y element, Ce was added into near-equiatomic AlNiY medium-entropy amorphous alloy (denoted as MEAA) ribbons by the melt spinning process in this study. The differences of microstructure, thermal stability, hardness and corrosion resistance of Al33.3Ni33.3Y33.4-xCex (x = 0, 2, 5, 8, 13) alloy ribbons were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), differential scanning calorimeter (DSC) and Vickers-type hardness tester. The anti-corrosion performance in 3.5 wt.% NaCl solution of alloy ribbons was investigated elaborately through the general potentiodynamic polarization curves (Tafel) and electrochemical impedance spectroscopy (EIS). Results suggested that all ribbon samples could remain amorphous structure and the hardness are all above 510 HV0.1. With the increase of Ce content, the thermal stability begins to be gradually lower. However, according to the analysis of crystallization kinetics, all types of MEAA ribbons presents the relatively prominent thermal stability compared with traditional Al-based amorphous alloys. The corrosion current density raises firstly, then shows a decreasing trend, and has a slight increase at last. Therefore, appropriate content of Ce element can improve the corrosion protection performance of alloy ribbons and the 5 at.% Ce MEAA ribbons exhibited the excellent corrosion resistance in this study.

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.

Artificial intelligence operated with machine learning was performed to optimize the amount of metalloid elements (Si, B, and P) subjected to be added to a Fe-based amorphous alloy for enhancement of soft magnetic properties. The effect of metalloid elements on magnetic properties was investigated through correlation analysis. Si and P were investigated as elements that affect saturation magnetization while B was investigated as an element that affect coercivity. The coefficient of determination R2 (coefficient of determination) obtained from regression analysis by learning with the Random Forest Algorithm (RFR) was 0.95 In particular, the R2 value measured after including phase information of the Fe-Si-B-P ribbon increased to 0.98. The optimal range of metalloid addition was predicted through correlation analysis method and machine learning.

The soft magnetic properties of Fe-based amorphous alloys can be controlled by their compositions through alloy design. Experimental data on these alloys show some discrepancy, however, with predicted values. For further improvement of the soft magnetic properties, machine learning processes such as random forest regression, k-nearest neighbors regression and support vector regression can be helpful to optimize the composition. In this study, the random forest regression method was used to find the optimum compositions of Fe-Si-B-C alloys. As a result, the lowest coercivity was observed in Fe80.5Si3.63B13.54C2.33 at.% and the highest saturation magnetization was obtained Fe81.83Si3.63B12.63C1.91 at.% with R2 values of 0.74 and 0.878, respectively.

The paper presents the results of research from the analysis of primary magnetization curves for Fe based amorphous alloys. Structural defects in the form of pseudodislocation dipoles occur in amorphous alloys. Using the theory developed by H. Kronmuller called the approach to ferromagnetic saturation, it is possible to indirectly observe internal stresses occurring in the volume of amorphous alloys. The magnetic structure is sensitive to all kinds of inhomogeneities that become visible in the process of high-field magnetization. It has been shown that the cooling rate of the liquid alloy has a great influence on the migration of atoms during the solidification process. Longer time of alloy formation causes more atoms to occupy ordered positions, which results in a change in the distance between the magnetic atoms and a higher degree of structure relaxation. This is indicated by a significant difference in the value of the spin wave stiffness parameter Dspf. The structural differences of the alloys were also investigated using a magnetic balance. It has been shown that the cooling rate influences insignificant differences in the course of thermomagnetic curves and the Curie temperature.