Glass-coated Microwires Research Articles

Pre-use interfacial shear strength prediction for fiber-reinforced thermosetting composites based on stress-impedance effect of ferromagnetic microwires

A new rapid evaluation method of composite interfacial shear strength (IFSS) on basis of impedance parameter utilizing the glass-coated cobalt-based ferromagnetic microwire (GCM) with sensitive stress-impedance effect is proposed. The intrinsic properties analysis and surface modification of GCM were performed to improve the sensitivity of stress-impedance effect and meet the application requirements in composites. The correlation between impedance increments and interfacial stress is investigated for GCM composites with different resin embedded lengths through experimental verification and finite element simulation. The impedance increment of microwire shows a high degree of dependence on IFSS of GCM/resin systems, which is mainly associated with the local interfacial stress from the resin. Based on this correlation mechanism and IFSS measured by microdroplet debonding test, IFSS of composites with different resin matrix were successfully calculated from the impedance parameter, and the interfacial bonding of resin matrix could be distinguished and sorted as relatively superior or inferior conveniently and rapidly. In comparison with the sophisticated, lengthy and expensive interface mechanical tests after the manufacture of fibers and resin, the pre-use efficient interfacial assessing of resin matrixes only using GCM shows potential to screen resin matrix with excellent interfacial properties towards advanced fiber-reinforced thermosetting resin matrix composite.

Study of martensitic transition temperature on Ni54Fe19Ga23X4 Heusler glass-coated microwires doped by X = B, Al, Ga, in

The influence of alloying in Ni54Fe19Ga23X4 Heusler glass-coated microwires doped by X = B, Al, Ga, In is presented in this work. Even though the alloys exhibit different chemical compositions, the valence electron concentration (e/a) was constant. Furthermore, basic magnetic and resistivity measurements have been performed to determine the chemical doping effect on the magnetic properties and the associated structural transformation. Results point to the fact that the fine-tuning of the chemical composition may be a suitable tool for adjusting the Curie temperature, transformation temperature, and magnetocaloric properties of the glass-coated microwires. In the case of Ga and the Al-doped alloy, a thermal hysteresis can be distinguished in the M(T) dependences at saturation magnetic field, pointing to the presence of the structural transformation. Moreover, the 4% Al doping shifts the structural transformation temperature and the Curie temperature almost to the same position. On the other hand, B and In doping may lead to the disappearance or shift of the structural transformation out of the measurement range (100–400 K). Resistivity measurements proved these results.

Mechanical Properties Test and Simulation Analysis of Glass Coated Amorphous Filaments

Taking the Co68.7Fe4Ni1B13Si11Mo2.3 glass-coated amorphous microwire as the research object, the mechanical properties of the amorphous wire were tested through biaxial tensile experiments, and the fracture deformation process of the amorphous wire was analyzed. Based on the experimental data, the finite element method was used The simulation software ABAQUS numerically simulates the tensile deformation of the amorphous wire, and the fracture relationship between the glass cladding layer and the core wire, and further reveals the tensile deformation fracture behavior of the amorphous wire was analyzed. The experimental results indicate that the fabricated microwires exhibit good tensile properties, and the maximum tensile breaking strength can reach 2918MPa; the fracture of the amorphous wire is a typical brittle fracture, and there is no obvious yield phenomenon. The tensile mechanics simulation results of the amorphous wire are consistent with the experimental results. The glass cladding layer breaks before the core wire, and the stress transfer effect in the amorphous wire is good. The model fracture is consistent with the fracture morphology of the amorphous wire. These results show that the amorphous wire exhibits good tensile properties and stress transmission capabilities, confirming the huge application potential of amorphous wire materials in sensor applications and functional composite materials.

Glass-coated microwires for composites

In this paper, solutions for two problems are proposed. One of the problems is associated with increasing the strength of objects, for instance, the strength of windows in industrial buildings and dwelling houses. The other problem is related to electromagnetic shielding. Both of these problems are related to the protection form terrorist acts, since terrorists make use of concentrated electromagnetic pulses to destroy computers or other electronic equipment. The proposed solutions are based upon the manufacturing of glass windows reinforced with cast glass-coated amorphous micro- and nanowires (CGCAMNWs) having a special composition and structure, which increases their tensile strength against mechanical destruction, on the one hand, and imparts them with shielding properties against electromagnetic radiation, on the other hand. The CGCAMNW materials are of interest from both theoretical and practical points of view.

Effect of Joule heating on giant magnetoimpedance effect and magnetic properties of Co-rich microwires

The effect of Joule-heating on hysteresis loops and giant magnetoimpedance effect, GMI; of Co69.2Fe3.6Ni1B12.5Si11Mo1.5C1.2 glass-coated microwire is studied. Joule heating performed at suitable conditions prevents the magnetic hardening observed during conventional furnace annealing of the studied microwires. A remarkable GMI ratio improvement is observed as compared to as-prepared annealed and even stress-annealed microwires. Observed magnetic softening and GMI ratio improvement have been discussed considering magnetic anisotropy induced by Oersted magnetic field during Joule heating and internal stresses relaxation.

Influence of Joule heating on electrical resistivity in Co-rich amorphous microwires

The paper investigates the electrical resistivity of two types of the glass-coated Co-rich amorphous ferromagnetic microwires during the Joule heating by direct current. We measured the relationships between the microwire’s resistivity and the power, which applied to the samples in as-prepared and crystallized conditions. Both types of microwires were demonstrated to completely crystallize on exposure to a temperature of more than 600 °C. During heating by a power up to 2.5 W (~400 °C), the microwires with Mo-Ni content were characterized by a monotonic resistivity increase with the temperature. But the microwires with Cr content had a well-marked resistivity minimum near the temperature Tм ~ 163 °C. This minimum shifted to a temperature value of ~260 °C after annealing. The research shows that the temperature dependence of resistivity in the temperature range below Tм obeys the f(T) = -ln(T) law.

Trinseo and ETB sign LOI to collaborate on developing bio-based 1,3-butadiene

The paper investigates the electrical resistivity of two types of the glass-coated Co-rich amorphous ferromagnetic microwires during the Joule heating by direct current. We measured the relationships between the microwire’s resistivity and the power, which applied to the samples in as-prepared and crystallized conditions. Both types of microwires were demonstrated to completely crystallize on exposure to a temperature of more than 600 °C. During heating by a power up to 2.5 W (~400 °C), the microwires with Mo-Ni content were characterized by a monotonic resistivity increase with the temperature. But the microwires with Cr content had a well-marked resistivity minimum near the temperature Tм ~ 163 °C. This minimum shifted to a temperature value of ~260 °C after annealing. The research shows that the temperature dependence of resistivity in the temperature range below Tм obeys the f(T) = -ln(T) law.

Glass-Coated Microwires For Composites

Serghei A Baranov1,2* Author Affiliations 1Institute of Applied Physics, str. Academiei 5, Chisinau, MD-2028 Republic of Moldova 2Shevchenko Pridnestrov’e State University, str. 25 Oktyabrya 128, Tiraspol, Republic of Moldova Received: May 08, 2021 | Published: May 28, 2021 Corresponding author: Serghei A Baranov, Institute of Applied Physics, str. Academiei 5, Chisinau, MD-2028 Republic of Moldova, Shevchenko Pridnestrov’e State University, str. 25 Oktyabrya 128, Tiraspol, Republic of Moldova DOI: 10.26717/BJSTR.2021.36.005804

Contribution to the study of the domain wall shape in bistable microwires

Magnetic domain wall in bistable glass-coated microwires is subject of the study in this paper. The domain wall between axial domains in these microwires is not a standard 180° domain wall. It is the source of a stray field, so the shape of the induced signal due to the domain wall passing through the pick-up coil is influenced by the domain wall geometry as well as by the presence of the stray field accompanying the moving wall. The present work considers the possibility of the moving domain wall having a stable conical-like shape with the apex pointing ahead. Based on this configuration, the signal induced in the pick-up coil is modelled. It is shown that the shape of the obtained model signal can explain the typical signals observed in experiments.

Electronic Surveillance and Security Applications of Magnetic Microwires

Applications in security and electronic surveillance require a combination of excellent magnetic softness with good mechanical and anticorrosive properties and low dimensionality. We overviewed the feasibility of using glass-coated microwires for electronic article surveillance and security applications, as well as different routes of tuning the magnetic properties of individual microwires or microwire arrays, making them quite attractive for electronic article surveillance and security applications. We provide the routes for tuning the hysteresis loops’ nonlinearity by the magnetostatic interaction between the microwires in the arrays of different types of amorphous microwires. The presence of neighboring microwire (either Fe- or Co-based) significantly affects the hysteresis loop of the whole microwires array. In a microwires array containing magnetically bistable microwires, we observed splitting of the initially rectangular hysteresis loop with a number of Barkhausen jumps correlated with the number of magnetically bistable microwires. Essentially, nonlinear and irregular hysteresis loops have been observed in mixed arrays containing Fe- and Co-rich microwires. The obtained nonlinearity in hysteresis loops allowed to increase the harmonics and tune their magnetic field dependencies. On the other hand, several routes allowing to tune the switching field by either postprocessing or modifying the magnetoelastic anisotropy have been reviewed. Nonlinear hysteresis loops have been also observed upon devitrification of amorphous microwires. Semihard magnetic microwires have been obtained by annealing of Fe–Pt–Si microwires. The observed unique combination of magnetic properties together with thin dimensions and excellent mechanical and anticorrosive properties provide excellent perspectives for the use of glass-coated microwires for security and electronic surveillance applications.

Post-Annealing Influence on Magnetic Properties of Rapidly Quenched Ni–Mn–Ga Glass-Coated Microwires

In this article, we showed how the post-annealing process affects the magnetic properties of rapidly quenched Ni-Mn-Ga glass-coated microwires. Microwires with Ni <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">63</sub> Mn <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sub> Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">25</sub> chemical composition, total diameter D = 54.6 μm and metallic nucleus diameter d = 26.7 μm, were prepared by the Taylor-Ulitovsky technique. The annealing temperature was fixed at 873 K, and the time was 1 and 10 h. The microwires were slowly cooled to room temperature after annealing. Based on thermomagnetic curves and hysteresis loops, we suggest crystallographic texture in the wires that considerably affect magnetic properties. The wires' internal structure indicates nanocrystalline state with radial micrometers and submicrometer grains distribution in the wire annealed during 10 h. A ferromagnetic-to-paramagnetic phase transition occurs around room temperature. No signs of a martensitic transformation were found. The difference in magnetization saturation, remanence, and Curie temperature values for 1- and 10-h annealed microwires indicates the influence of internal stresses and that created by the presence of a glass coating.

Domain wall mobility engineering by a perpendicular magnetic field in microwires with a gradient of perpendicular anisotropy

Fast domain wall propagation is a typical feature of amorphous glass-coated microwires with positive magnetostriction. The high domain wall velocity can be effectively tailored either by sample postprocessing or temperature. In this work, we show that the domain wall dynamics can be engineered by a perpendicular magnetic field. We perform the domain wall mobility measurements in microwires with a varying gradient of the perpendicular magnetic anisotropy. It is shown that domain wall mobility is mainly determined by counterplay between the amplitude of perpendicular anisotropy and externally applied perpendicular field. The presence of perpendicular magnetic anisotropy is observed by Scanning electron microscopy. The relation between the maximum applied perpendicular magnetic field, and the wire dimensions are provided based on the measured data.

Changes in geometry of propagating domain wall in magnetic glass-coated bistable microwire

Domain wall dynamics in magnetic bistable glass-coated microwire were studied. A new experiment is presented which can provide information about propagating domain wall geometry and its changes. The proposed experimental set-up and data processing provide information about spatial distribution of axial magnetic flux around a propagating domain wall. The measurements were carried out on an Fe-based microwire with unidirectional effect. Shortening of the wall with applied magnetic field was observed. It was probably a stray field around a head-to-head (or tail-to-tail) domain wall which caused the observed effect to lack strength. Despite this fact it was confirmed that increasing damping of domain wall motion resulted in the wall shortening. The observed behaviour can be interpreted as a combined effect of eddy current damping and a conical type of wall with the apex at the head of the propagating wall.

Casting glass coated microwires of alloys based on silver and nickel

This work presents the results of studying the features of the casting process of glass-coated microwires of alloys based on silver, which has a near-zero TCR, and nickel, which has a high thermo emf.

A domain wall creation paradigm: Realization for amorphous Fe-based microwires

The creation of a domain wall pair in the magnetic core of amorphous glass-coated bistable microwires with circular cross-section is studied. Energy balance is formulated in the spirit of particle decay, equalizing magnetic field work and energy of two domain walls, emitted in opposite directions. The critical nucleation field is evaluated and compared with observations.

An Indirect Method of Micromagnetic Structure Estimation in Microwires.

The tunable magnetic properties of amorphous ferromagnetic glass-coated microwires make them suitable for a wide range of applications. Accurate knowledge of the micromagnetic structure is highly desirable since it affects almost all magnetic properties. To select an appropriate wire-sample for a specific application, a deeper understanding of the magnetization reversal process is required, because it determines the measurable response (such as induced voltage waveform and its spectrum). However, the experimental observation of micromagnetic structure of micro-scale amorphous objects has strict size limitations. In this work we proposed a novel experimental technique for evaluating the microstructural characteristics of glass-coated microwires. The cross-sectional permeability distribution in the sample was obtained from impedance measurements at different frequencies. This distribution enables estimation of the prevailing anisotropy in the local region of the wire cross-section. The results obtained were compared with the findings of magnetostatic measurements and remanent state analysis. The advantages and limitations of the methods were discussed.

The Design and Production of a Suitable Carrier for Microwires Used for Non-Contact Detection of Mechanical Strains

During the loading process, strain gauges connected to measuring devices are usually used to detect the strains of structural load-bearing members. Nowadays, newer and more sophisticated measurement methods are being developed. One of these involves the application of amorphous glass-coated microwires for non-contact detection of mechanical strains. This paper presents the results of research work aimed at finding a suitable carrier or transfer medium for such microwires. The identification of a suitable transfer medium was part of extensive theoretical and experimental research focusing on non-contact detection of mechanical strains based on amorphous glass-coated microwires. The results present an innovative and effective approach for sustainable practices in various fields of construction activity.

Vertical interface augmented tunability of scattering spectra in ferromagnetic microwire/silicone rubber metacomposites

Previously, we have demonstrated a viable approach based on microstructural and topological modulation of periodically arranged elements to program wave scattering in ferromagnetic glass-coated microwire metacomposites. In order to fully exploit the intrinsic structure of the composite, here, we implement the concept of composites plainification by an in-built vertical interface on randomly dispersed short-cut microwires allowing the adjustment of electromagnetic properties to a larger extent. Such interface was modified through arranging wires with different internal structures in two separated regions and by alternating these regions through wire concentration variations associated with polarization differences across the interface. When the wire concentration was equal in both regions, two well-defined transmission windows with varied amplitude and bandwidth were generated. Wire concentration fluctuations resulted in strong scattering changes ranging from broad passbands to pronounced stopbands, demonstrating the intimate relationship between wire content and space charge variations at the interface. This provides a new method to rationally exploit interfacial effects and microstructural features of microwire metacomposites. Moreover, the advantages of enabling tunable scattering spectra by merely 0.053 vol.% of fillers and simple structure make the proposed plainification strategy instrumental to designing filters with broadband frequency selectivity.

Modeling the Giant Magnetoimpedance Effect in Amorphous Microwires with Induced Magnetic Anisotropy

The giant magnetoimpedance effect in a glass-coated Fe-based amorphous microwire annealed under stresses is theoretically studied. The magnetization distribution in a microwire is described within a model that takes into account the presence in the sample of two regions with different types of magnetic anisotropy. It is assumed that, in the central part of the microwire, the anisotropy is longitudinal and, in the surface region, an induced helicoidal anisotropy arises as a result of annealing. An expression for the impedance of the microwire with allowance for different permeabilities of the two regions is found. The obtained theoretical dependences of the impedance on an external field and frequency make it possible to qualitatively describe the results of experimental studies of the magnetoimpedance in glass-coated Fe-based amorphous microwires.

Highly oriented ferromagnetic polymers based on Co- and Fe-rich amorphous microwires

In this paper highly oriented magneto-polymer composites have been obtained by means of Co and Fe-rich glass-coated amorphous microwires with various metal nucleus and outer diameters. The microwire segments with length L ~ 0.5–0.6 cm were oriented in the magnesium alloy matrix and were poured with a liquid polymer whose composition was a mixture of methyl methacrylate methacrylic acid and methacrylate copolymers in a ratio of 37/63% by mass. The magneto-polymer composites obtained possess high electric resistance, chemical stability and mechanical strength. The high average saturation magnetizations, <Ms> = 20–30 emu/cm3, have been obtained for Co and Fe based composites with the volume fraction of the magnetic material in the polymer matrix within the range 0.02–0.05. Both Co and Fe based composites show highly anisotropic magnetic properties. The magneto-polymer samples can be cut into pieces of arbitrary size and shape. This facilitates their use in various technical applications.