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We have grown and characterized (110)-oriented YBa2Cu3O7−x (YBCO)/PrBa2(Cu0.8Ga0.2)3O7−x (PBCGO) bilayer and YBCO/PBCGO/YBCO trilayer heterostructures, which were deposited by pulsed laser deposition technique for the nanofabrication of (110)-oriented YBCO-based superconductor (S)/insulator (I)/superconductor (S) tunneling vertical geometry Josephson junction and other superconductor electronic devices. The structural properties of these heterostructures, investigated through various x-ray diffraction techniques (profile, x-ray reflectivity, pole figure, and reciprocal mapping), showed (110)-oriented epitaxial growth with a preferred c-axis-in-plane direction for all layers of the heterostructures. The atomic force microscopy measurement on the top surface of the heterostructures showed crack-free and pinhole-free, compact surface morphology with about a few nanometer root mean square roughness over the 5 × 5 μm2 region. The electrical resistivity measurements on the (110)-direction of the heterostructures showed superconducting critical temperature (Tc) values above 77 K and a very small proximity effect due to the interfacial contact of the superconducting YBCO layers with the PBCGO insulating layer. Raman spectroscopy measurements on the heterostructures showed the softening of the Ag-type Raman modes associated with the apical oxygen O(4) and O(2)-O(3)-in-phase vibrations compared to the stand-alone (110)-oriented PBCGO due to the residual stress and additional two Raman modes at ∼600 and ∼285 cm−1 frequencies due to the disorder at the Cu–O chain site of the PBCGO. The growth process and structural, electrical transport, and Raman spectroscopy characterization of (110)-oriented YBCO/PBCGO bilayer and YBCO/PBCGO/YBCO trilayer heterostructures are discussed in detail. [ABSTRACT FROM AUTHOR]

The complex permeability and power losses are very important parameters for soft magnetic materials. In this paper, the temperature dependence of these two parameters is investigated for Mn–Zn ferrite. The Hopkinson peak was observed at 440 K below the Curie temperature (TC), and the domain-wall resonance peaks and the natural resonance peaks gradually move to lower frequencies until the Hopkinson temperature (TH). Further, the domain-wall resonance peaks from relaxation type to resonance type are observed by fitting the permeability spectrum, which is related to the reduction of the loss factor. In addition, the power losses were measured from 245 to 365 K and divided into hysteresis loss (Ph), eddy current loss (Pe), and excess loss (Pexc). Each loss contribution was discussed to be dependent on temperature. The results show that at high temperatures and high frequencies, the thermal superposition effect will cause an abnormal increase in excess loss. [ABSTRACT FROM AUTHOR]

Optimized heat treatment processes for high-strength, low-alloy steel are studied in order to maximize the strengthening effects of the alloying elements and achieve a favorable balance of strength and ductility. In this study, it is found that high-energy-density electric pulse treatment (EPT) can effectively reduce the residual stress in quenched high-strength, low-alloy steel. Furthermore, EPT promotes the precipitation of fine needle-like ε-carbides and small spherical M6C carbides. Using an electrical pulse acting for 10 s with a current density of 19.52 A/mm2, the elongation of the quenched steel increases from 4.5% to 12.4%. Compared to the as-quenched state, there is no significant decrease in tensile strength, while the product of strength and ductility reaches 20.33 GPa%. When the pulse current density is increased to 27.76 A/mm2 for 10 s, the tempering effect is equivalent to that of tempering at 600 °C for 4 h. [ABSTRACT FROM AUTHOR]

In this study, how crystallographic texture and changes in microstructure affect the magnetic properties of a semi‐processed non‐oriented (NO) electrical steel, which is investigated in its as‐received state and after heat treatment, is evaluated. Electron backscattered diffraction analysis shows the variation in texture with a crystallographic orientation changing from a predominance of γ and α fibers to a random one after heat treatment, with a significant increase in components with <100> directions in the sheet plane, which are desired for NO steels because they are parallel to the direction of easy magnetization. Heat treatment has also increased the average grain size of the samples from 18 to 128 μm. Magnetic properties are analyzed over a wide frequency range and induction, presenting different behaviors in permeability and magnetic loss for the samples before and after heat treatment. The components of total magnetic loss are also evaluated, and the hysteresis loss of heat‐treated sample decreases significantly. This demonstrates that heat treatment reduces microstructural imperfections, causing a decrease in hysteresis losses. Therefore, it is concluded that the improvement in magnetic performance observed with heat treatment has its origin in the increase in fiber components related to the <100> directions and a decrease in microstructural imperfections. [ABSTRACT FROM AUTHOR]

The iron core of non-oriented electrical steel sheets is manufactured by punching, and the punching clearance greatly affects the amount of iron loss. Empirically, it is known that increasing the punching clearance, while extending the life of the die, introduces greater plastic deformation at the end of the iron core. This plastic deformation increases iron loss and decreases motor performance, making clearance a condition that must be controlled. On the other hand, punching clearance is proprietary information of the manufacturer and is not disclosed unless it is produced in-house. Against this background, we have developed an inspection method for estimating punching clearance, to better control the quality of iron cores. First, ring specimens were prepared using die with different clearances (0.6%-16.4%). Magnetic property evaluation for these ring specimens showed a linear relationship where iron loss increased with increasing clearance. The electron backscattering diffraction (EBSD) analysis pointed to the changes in strain introduction at the machining edge. Discussion of these data resulted in a calibrated relationship between clearance and kernel average misorientation (KAM). In addition, similar tests were performed on several grades of nonoriented electrical steel sheets to obtain a versatile calibration curve that takes in to account the effect of hardness. The results and discussion of this study demonstrate a new estimation technique that is expected to contribute to motor production management. [ABSTRACT FROM AUTHOR]

The presence of island grains in the initial finished sheets of grain-oriented electrical steel is inevitable in the preparation of ultra-thin strips. Owing to their distinctive shape and size effects, their deformation behavior during rolling differs from that of grain-oriented electrical steels of conventional thickness. This study focuses on the orientation evolution and deformation heterogeneity of island grains during rolling. Four types of island grains with orientations of {210}<001>, {110}<112>, {114}<481>, and {100}<021> were selected and modeled within the Goss-oriented matrix using full-field crystal plasticity finite element (CPFEM) simulation under plane strain compression. The results are then compared with corresponding experimental measurements. The results reveal that orientation rotation and grain fragmentation vary among the island grains of different orientations, with the first two orientations exhibiting more significant deformation heterogeneity compared to the latter two. Additionally, the orientations of the island grains significantly affect the distribution of residual Goss orientations within the surrounding matrix. Pancake-like island grains exhibit a higher degree of orientation scatter and greater deformation heterogeneity in the central layer compared to their spherical counterparts. The initial {210}<001> island grains can form a cube orientation, which can be optimized by subsequent process control to enhance magnetic properties. [ABSTRACT FROM AUTHOR]

The Magnetic Barkhausen Noise (MBN) is a non-destructive testing method, which, due to its high sensitivity to changes in the microstructure of the material, is increasingly being applied with success as a tool for evaluation of magnetic material state and properties. However, it is no less difficult to analyze the measurement signals and their correct interpretation due to the complex, non-deterministic and stochastic nature of the Barkhausen phenomenon. Depending on the material to be examined, a signal with different characteristics can be observed. Frequently, a signal with multi-phase Barkhausen activity characteristics is obtained, like in the case of grain-oriented electrical steels. Due to the increased computational capabilities of computers, more and more advanced signal analysis methods are being used and artificial intelligence is being involved as well. Recently, the time–frequency (TF) approach for MBN signal analysis was introduced and discussed in several papers, where short-time Fourier Transform (STFT) found frequent application with promising results. Due to the automation of the search for diagnostic patterns, the stage of selecting transformation parameters becomes extremely important in the process of preparing training data for evaluation algorithms. This paper investigates the influence of the STFT computational window size on the material state evaluation results obtained using convolutional neural network (CNN). The studies were performed for MBN signals obtained from grain-oriented electrical steel with anisotropic properties. The carried out work made it possible to draw connections on the importance of the choice of the window during the implementation of CNN network training. [ABSTRACT FROM AUTHOR]

This study investigates the effectiveness of in-situ urea-assisted nitriding during electrical discharge machining (EDM) as a novel approach to enhance the fatigue performance of AISI 4140 steel. EDM is known to introduce surface defects and tensile residual stresses that compromise fatigue strength. By employing a urea-based dielectric solution, this method forms a protective nitride layer on the steel surface, which addresses these issues. Experimental results demonstrate significant improvements in fatigue life for nitrided specimens, with an increase of 24% at a stress amplitude of 388 MPa and up to 14-fold at 242 MPa. Additionally, surface tensile residual stresses were reduced by 26% in nitrided specimens. These enhancements are attributed to the formation of the nitride layer, which improves fatigue resistance and surface integrity. Compared to traditional nitriding methods, in-situ urea-assisted EDM nitriding offers several advantages, including the ability to simultaneously form the nitride layer and machine the component, reducing processing time and costs. This work underscores the promising potential of in-situ urea-assisted EDM nitriding as an effective strategy for improving the fatigue performance of AISI 4140 steel components and suggests directions for future research in surface modification techniques. [ABSTRACT FROM AUTHOR]

Hot rolling is a critical thermomechanical processing step for nonoriented electrical steel (NOES) to achieve optimal mechanical and magnetic properties. Depending on the silicon and carbon contents, the electrical steel may or may not undergo austenite–ferrite phase transformation during hot rolling, which requires different process controls as the austenite and ferrite show different flow stresses at high temperatures. Herein, the high‐temperature flow behaviors of two nonoriented electrical steels with silicon contents of 1.3 and 3.2 wt% are investigated through hot compression tests. The hot deformation temperature is varied from 850 to 1050 °C, and the strain rate is differentiated from 0.01 to 1.0 s−1. The measured stress‐strain data are fitted using various constitutive models (combined with optimization techniques), namely, Johnson–Cook, modified Johnson–Cook, Zener–Hollomon, Hensel–Spittel, modified Hensel–Spittel, and modified Zerilli–Armstrong. The results are also compared with a model based on deep neural network (DNN). It is shown that the Hensel–Spittel model results in the smallest average absolute relative error among all the constitutive models, and the DNN model can perfectly track almost all the experimental flow stresses over the entire ranges of temperature, strain rate, and strain. [ABSTRACT FROM AUTHOR]

Cu- and Mn-based spinel coatings are currently among the most promising materials for solid oxide electrolyzer cell (SOEC) interconnects due to their high electrical conductivity and ability to eliminate environmentally hazardous cobalt, which is included in the most widely used coatings. However, their properties are affected by the presence of the Cr2O3 scale and high-temperature corrosion, and to mitigate this they could be doped with elements such as Ni and Fe. In addition, the electrical properties of such steel/shell layered systems can be further improved using rare-earth element nanoparticles (Ce0.9Y0.1O2). In this work, low-chromium steel was modified using nanoparticles and/or spinel coatings and oxidized in air atmosphere at 800 °C for 2000 hours. The oxidized systems were then characterized using diffraction studies, microstructural observations and electrical measurements. Electrical studies in particular showed a significant reduction in area-specific resistance for steels modified using a combination of both nanoparticles and spinel coatings. [ABSTRACT FROM AUTHOR]

In this study, electrical steel laminated composites with positive Si gradient (PO-G), counter Si gradient (CO-G), and cross Si gradient (CR-G) were fabricated by hot-press sintering, cold rolling and annealing. The microstructure evolution during processing, as well as the magnetic and mechanical properties were investigated. The results indicate that the microstructure of the high-silicon layer and medium-silicon layer in the hot-pressed composites featured columnar grains throughout the thickness. The microstructure of the low-silicon layer in the hot-pressed CO-G sample consisted of equiaxed grains. However, a mixed structure dominated by columnar grains with some equiaxed grains was observed in the inner low-silicon layer of the PO-G and CR-G samples. Following cold rolling, the thickness ratio of each layer remained largely unchanged. After annealing, the microstructure of each layer transformed into columnar grains. The average grain size of the high-silicon layer, medium-silicon layer, and low-silicon layers in the three composites were approximately 20–23 μm, 33–38 μm, and 42–49 μm, respectively. Compared with the CO-G and CR-G samples, the annealed PO-G composite exhibited lower core loss at 400–1000 Hz and superior tensile strength. Furthermore, the core loss of the three composites was greater than that of the initial medium-silicon and high-silicon materials. This can be attributed to the increased hysteresis loss due to the existence of multi-layer interface. [ABSTRACT FROM AUTHOR]

The fatigue behavior of a fully processed, non-oriented electrical steel sheet is investigated in dependence on shear-cutting parameters and a subsequent heat treatment. For this, stress-controlled fatigue tests are performed before and after annealing at 700 °C for a total of six different shear-cutting settings. For all parameters, the fatigue strength of shear-cut sheets is improved by the heat treatment. This is due to reduction in a large part of the strain hardening region as well as the reduction in tensile residual stresses. Both were introduced during shear cutting and act detrimental to the fatigue strength. However, the intensity of this improvement depends on the shear-cutting parameters. This is related to the corresponding edge surfaces characteristically being formed during shear cutting. Specimens cut with a worn cutting tool show a more pronounced increase in fatigue life. In contrast, specimens produced with a sharp-edged cutting tool and high cutting clearance hardly benefit from the heat treatment. This appears to be caused by differences in surface topography, in particular coarse topographical damage in the form of grain breakouts. If these occur during shear cutting, the crack formation is not significantly delayed by additional annealing. [ABSTRACT FROM AUTHOR]

Planar flow casting is a high-efficiency and energy-saving method to manufacture non-oriented silicon steel ultra-thin ribbons. In this study, we prepared Fe−3.0 wt pct Si non-oriented silicon steel ultra-thin ribbons with this process and investigated the effects of different annealing temperatures and durations on the microstructure and magnetic properties of the as-cast ribbons. The results show that the surface grain size gradually increases with elevated annealing temperature. However, the annealing duration has a relatively minor influence on grain growth, only a modest increase during 900 °C annealing. Meanwhile, the favorable {100} texture diminishes while the {110} and {111} texture intensifies with increasing annealing temperature and duration, leading to an overall gradual decline in magnetic induction owing to texture degradation. Notably, the iron loss undergoes a significant initial reduction due to the sharp decrease in dislocation density after annealing. Subsequently, as the annealing temperature and time increase, the iron loss gradually decreases, primarily because of the increase in grain size. [ABSTRACT FROM AUTHOR]

Concrete is a constantly evolving building material whose demand is increasing due to population growth and urban development. This calls for more research on this composite material to improve its performance. However, concrete has some disadvantages, including that it is a brittle material and cannot withstand tensile stress. Therefore, rebars and fibers are incorporated into concrete to improve this property. Although previous works investigated the properties of concrete containing steel fibers, most of them were concerned with mechanical properties, while the durability properties still require further investigation to understand them. Thus, the purpose of this study is to ascertain how adding steel fibers to concrete in varying proportions (0.5, 1.0 and 1.5%) affects its mechanical and durability properties, including compressive strength, flexural strength, tensile strength, bulk density, water absorption, mode of failure, ultrasonic pulse velocity, dynamic modulus of elasticity and electrical resistance. Statistical relationships between the compressive strength and other characteristics were also established. The results indicated that all mechanical and durability characteristics significantly improved after adding steel fibers for all addition ratios, except for electrical resistivity, which showed lower values than the reference mixture for the 0.5 and 1% steel fiber proportions. Moreover, it was found that the best addition rate of steel fibers was 1.5%. At this percentage, the recorded increasing rates over the control sample were 29.3% in compressive strength, 83.7% in tensile strength, 27.9% in flexural strength, 50.1 in water absorption resistance, and 11.2% in electrical resistivity. [ABSTRACT FROM AUTHOR]

Blue laser spot welding electrical steel can improve material absorption, stabilise the molten pool and reduce heat input. The influence of process parameters on the welding quality of blue laser spot welding electrical steel is investigated. With the increase of laser power, a 'single hump' molten pool was generated. At the power of 1000 W, the melting mode changed, and the plume appeared above the molten pool. The maximum penetration depth was 0.75 mm (laser power 1000 W, pulse time 1 s). Higher laser energy led to a continuous increase in the proportion of columnar grains, exceeding 45% at 1000 J. Finally, higher laser power and pulse time enhanced the connection and bonded area of laminations. [ABSTRACT FROM AUTHOR]

Herein, laboratory experiments are conducted to evaluate the effect of sulfur and lanthanum content in the steel on the modification of inclusions. The amount, composition, morphology, and size of nonmetallic inclusions in the steel are observed using an automatic scanning electron microscope. Results show that as the lanthanum content in the steel increased from 0 to 72 ppm, the inclusions in the steel with 12 ppm sulfur are modified in the following order: Al2O3–CaO–MgO → LaAlO3 → LaAlO3–La2O2S → La2O2S. Similarly, when the sulfur content is 27 ppm, inclusions transformed in the order of Al2O3–CaO–MgO → LaAlO3 → LaAlO3–La2O2S → La2O2S → La2O2S–LaxS → LaxS as the lanthanum content increases from 0 to 150 ppm. Thermodynamic analysis using FactSage based on a private database is employed to reveal the mechanism for the modification of inclusions. Additionally, a kinetic model is established to study the transformation rate of inclusions in the steel after the addition of lanthanum and sulfur. Liquid Al2O3–CaO–MgO inclusions disappear after 800 s when the steel contains 12 ppm sulfur and 12 ppm lanthanum. The composition of inclusions is 53%LaAlO3–47%La2O2S at 1800 s, while it is 100%La2O2S and 80%La2O2S–18%LaxS–2%CaS when the lanthanum content is 33 and 72 ppm, respectively. [ABSTRACT FROM AUTHOR]

The possibility of using plasma-liquid welding with direct current electric discharge at atmospheric pressure to manufacture products from electrical steel E-310 is studied. The samples are welded by immersing a metallic cathode (the welded parts) into a liquid (non-metallic) anode. The electrophysical parameters of the welding process are determined, including the current-voltage characteristic and the current and voltage fluctuations. The results of the analysis of the morphology and of the microhardness of the weld are presented. The prospects of plasma-liquid welding of parts from electrical steel E-310 are demonstrated at an appropriately chosen mode of the variable resistor. [ABSTRACT FROM AUTHOR]

The TMS Board of Directors recently approved professional membership for a diverse group of new members from countries like the United States, Pakistan, Canada, and Zimbabwe, representing institutions ranging from universities to technology companies. This decision underscores TMS's commitment to inclusivity and collaboration within the minerals, metals, and materials science field. The list of new members welcomed in May and August 2024 includes individuals from various countries and institutions, showcasing a global community of researchers and professionals working together in fields like materials science and engineering. The document highlights international collaboration and knowledge exchange among researchers and professionals from countries such as the United States, Japan, Germany, and South Korea, emphasizing the importance of global partnerships in advancing scientific research efforts. [Extracted from the article]

Baiyun Ebo ore in Inner Mongolia in China is an associated ore rich in RE, Nb, Ti and other elements, which still have trace residues after smelting. In order to promote the comprehensive utilization of superior mineral resources and give full play to the role of these alloying elements in steel, the microstructure, texture and precipitates evolution of non-oriented silicon steel containing Nb were studied in different annealing processes in this research. The results show that when the non-oriented silicon steel containing Nb is annealed at 850°C, with the extension of annealing time, the recrystallized grains preferably nucleate and grow in the deformation band and grain boundary on the surface of the annealing plate. When the holding time is 3 min, the recrystallization proportion is about 20%. When the holding time reaches 9 minutes, recrystallization occurs completely, and the final recrystallization texture is mainly {111}<112> orientation. The precipitates of the steel is mainly Fe16Nb6Si7 after annealing, the particle size can reach 100 nm. When annealed at 850°C, the volume fraction of Fe16Nb6Si7 phase decreases with the increase of annealing time, from 0.03236% to 0.01036%. When annealed at 850 °C for 3 min, the strength of the second phase increases to 9.4 MPa, and when the annealing time reaches 9 min, the strength of the second phase increases to 3.88 MPa. Therefore, when annealed at 850 °C, the precipitation of Fe16Nb6Si7 particles has little effect on the intensity increment. In the design of annealing process, the Nb-rich phase should be solid dissolved into the matrix as much as possible, on one hand, the adverse effects of particles on magnetic induction and iron loss are reduced, on the other hand, the strength of non-oriented silicon steel can be improved by solid solution strengthening. [ABSTRACT FROM AUTHOR]

Toroidal cores based on nanocrystalline powder Fe73Si16B7Cu1Nb3 (of Finemet type) and Portland cement 'M-500' as a binder are fabricated using powder metallurgy methods (where no pressing is applied). The cores exhibit reliable strength, temperature resistance up to 300°C, and excellent magnetic properties. Using these composites provides lower losses and more stable frequency characteristics of the cores as compared to the cores for power electronics based on carbonyl-iron powders, AlSiFe, or high-silicon electrical steel. Additionally, such composites can be used for production of the devices operating at elevated temperatures, e.g., magnetic flux concentrators for induction heaters. Since these soft magnetic composites do not require pressing operations, the cores' manufacturing process is simplified significantly and enables diversification of core shapes and sizes. [ABSTRACT FROM AUTHOR]

We are entering an era of re-electrification, seeking high-power density electrical machines with minimal resource use. Significant performance gains in electrical machines have been achieved through precise manufacturing processes, including the shaping/cutting of soft magnetic materials. However, most studies have evaluated magnetic performance at a macro level, focusing on components, while the fundamental mechanisms, e.g., how the micromagnetic behaviour is affected by mechanical interference, remain unclear. In this study, we examine the impact of sub-micron deformations at opposing strain rates (10−2 to 101 s−1) on the micromagnetic behaviour of soft magnetic non-oriented electrical steel. Using a diamond probe to indent within a single grain of polycrystalline material at different velocities, we induce quasi-static and dynamic mechanical loading. Our analysis, employing magnetic force microscopy, transmission Kikuchi diffraction, and scanning transmission electron microscopy with a pixelated detector, reveals that magnetic texture disturbances rely on the time-dependent dislocation dynamics of the Fe-BCC material. Additionally, we compress micro-pillars to further investigate these effects under bulk-isolated deformation. These findings highlight the importance of considering even ultra-small loads, such as nano-indentations and micro-pillar compressions, in the manufacturing of next-generation electric machines, as they can affect magnetic texture and performance. Mechanical deformations affect magnetic properties of electrical steels, impacting machine efficiency. Here, authors demonstrate that sub-micron deformations at different strain rates alter micromagnetic behaviour of non-oriented electrical steel due to time-dependent dislocation dynamics. [ABSTRACT FROM AUTHOR]

The paper presents the model of stress dependence of 2D relative magnetic permeability of anisotropic, grain-oriented M120-27s electrical steel suitable for finite element method modeling. The proposed model was developed based on experimental results acquired using the measuring setup with a testing yoke equipped with a Cardan gyroscopic mechanism and hydraulic press. In the presented model, parameters of the tensor description of 2D relative magnetic permeability were chosen during the feature selection process and identified during differential evolution optimization. The good quality of the proposed model was quantitatively confirmed by the R-squared coefficient, which exceeds 0.997 for all plots of the 2D relative magnetic permeability tensor. [ABSTRACT FROM AUTHOR]

In this paper, dynamic anti-plane problem in graded non-homogeneous magnetic-electric-elastic material with a conductive cylindrical rigid inclusion is studied. Cracks are generated from the inclusion edge under the action of SH guided waves. By applying a pair of reversed shear stresses to the crack surface, the mechanical model of the crack is achieved, and Green's function method is used in this process. The scattering fields of displacement, electric potential and magnetic potential are constructed by the wave function expansion method. Numerical results clarified the factors that affect the dynamic stress intensity factor of the crack tips, including material parameters, inclusion parameters, wave number and incident angle. It is expected that the investigation of magnetic-electric-elastic material with inclusion-initiated crack defects can provide some references for the project designing, manufacture and application of non-homogeneous multi-fields coupling materials. [ABSTRACT FROM AUTHOR]

To investigate the impact of diverse multivariate mixing excitation conditions on the hysteresis loop of ferromagnetic materials, this study initially constructs a magnetic performance testing system for electrical steel. This system is capable of generating mixed excitation utilizing a standard Epstein square‐circle setup. Subsequently, the study measures the magnetic properties of the oriented silicon steel sheets at various mixing AC frequencies of the hysteresis loop data. Secondly, a hybrid network model integrating a convolutional neural network (CNN) and a bi‐directional long short‐term memory network (BiGRU), augmented with an attention mechanism (AM), is proposed and utilized for predicting the hysteresis properties of oriented silicon steel wafers subjected to compound mixed‐frequency excitation. The model utilizes CNN to extract high‐dimensional data features reflecting the hysteresis characteristics of the loop, BiGRU to capture the temporal evolution patterns of the key feature vectors, an AM to weigh the feature parameters and emphasize the key features, and a Bayesian optimization (BO) algorithm based on neural network hyperparameters for automatic selection, enhancing prediction accuracy. In comparison with experimental observations, the method accurately predicts material hysteresis properties under non‐sinusoidal complex excitation conditions, outperforming existing deep‐learning network models. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The document discusses the importance of heat treatment in modifying the microstructure of metals to achieve desired properties. It highlights research papers on various heat treatment methods and their effects on different alloys, including bearings, martensitic stainless steel, electrical steels, and high resistance steel. The studies focus on optimizing heat treatment parameters to enhance mechanical and magnetic properties, with implications for industrial applications. The document also presents a method for manufacturing low-cost heat pipes with specific properties and geometry using basic tools and 3D printers. [Extracted from the article]

Density, surface tension, and viscosity of various liquid electrical steels are measured at different temperatures, varying in their silicon content between 3 and 6 mass%. Density and surface tension are determined using the maximum bubble pressure method, while viscosity is investigated comparatively using a vibrating finger viscometer and an oscillating crucible viscometer. The results are compared with models known from the literature. Based on this, the density of the steel [ρ] = kg m−3 and the surface tension [σ] = N m−1 can be described as a function of temperature [θ] = °C and silicon content [Si] = mass% using the equations: ρ(θ,Si)=−1.28×θ−104.18×Si+9081.8, σ(θ,Si)=10−4×[ −0.00903×θ2−1.21494×Si2+29.268×θ−1.987×Si−22334 ]. There is a lack of experimental data in the literature for high‐temperature thermophysical properties for electrical steels. This underlines once again the novelty and significance of this study, as the determined thermophysical properties are essential for a wide range of applications. For instance, they are crucial in the production of metallic powders for additive manufacturing by atomization to adjust the properties of the powders precisely. The findings are also important for steelmaking itself, as the corrosion behavior of refractory material can be better determined. [ABSTRACT FROM AUTHOR]

The effects of Si content of steel melts containing 1.5% Al as well as alloying sequence of Si and Al on the evolution of inclusions are investigated. The SiO2 inclusion is primarily formed when Si (=0.5–3.0 wt%) is added to the melts at 1873 K, and the area fraction (AF) of the inclusions decreases over time. The subsequent addition of 1.5% Al to the Si‐alloyed steel (i.e., 3.0Si→1.5Al) increases the AF of inclusions due to the formation of Al2O3. The population density function (PDF) analysis for the preferential Si alloying shows a fractal distribution, indicating that the inclusions grow by a collision mechanism. PDF analysis shows a lognormal distribution because Al2O3 inclusion is formed and grows after subsequent Al alloying. Alternatively, when 1.5% Al is preferentially added to steel, Al2O3 clusters are formed. The AF of Al2O3 cluster decreases over time. When 3.0% Si is subsequently added to the Al‐alloyed steel (i.e., 1.5Al→3.0Si), singular Al2O3 particles are mainly observed. Because the Al alloying results in the formation of Al2O3 regardless of the alloying sequence and Si content, it is important to float up and separate Al2O3 cluster to improve the cleanliness of high‐Si‐Al‐alloyed steels such as electrical steels. [ABSTRACT FROM AUTHOR]

The present study reports the synthesis of cobalt ferrite nanoparticles (CoFe 2 O 4 NPs) using the sol-gel precipitation process via mixing a stoichiometric ratio of cobalt chloride (1 M) and ferric chloride (2 M). The molar of ferric to cobalt was mentioned (2:1) and then 2 M of sodium hydroxide was added. The structural and morphological features of the material were assessed using X-ray diffraction (XRD), Scanning electron microscopy (SEM), and atomic force microscopy (AFM). The electrical properties were analyzed using an LCR meter, while the magnetic properties were measured using a vibrating sample magnetometer (VSM). Fourier-transform infrared spectroscopy (FTIR) investigated the material's molecular vibrations. The X-ray diffraction (XRD) analysis revealed that all the samples exhibited a cubic spinal structure, and no additional peak was detected. Interestingly, the average size of the crystallites (D) decreased from 17.74 nm to 16.58 nm as the pH level increased from 7 to 13. This finding provides important insights into the behaviour of the tested samples under different pH conditions. The formation of the ferrite spine was confirmed by FTIR spectroscopy, with the primary detected bands (408.92–470.65 cm−1) attributed to the octahedral complexes and (516.94–588.31 cm−1) assigned to the tetrahedral ones. The dielectric and imaginary part of the dielectric constant decreased with increasing pH values excluding samples prepared at pH = 11. All samples with different pH values exhibit resonance peaks at frequencies up to (1 KHz). The magnetic measurements carried out by the VSM instrument, the result show that the saturation magnetization increases with increasing pH and the higher saturation magnetization is 68 emu. g1. [ABSTRACT FROM AUTHOR]

This article proposes a design of windings for medium-frequency transformers (MFTs) at the heart of high-power Solid-State Transformers (SSTs). With aluminum interleaved foils of the correct thicknesses, it is possible to obtain low winding losses and a very low leakage inductance well adapted to high-power SSTs able to operate in the medium-voltage grid (5–20 kV). The MFT equivalent resistance and leakage inductance are determined using an analytical model based on Dowell's hypotheses. Several interleaved winding configurations are analyzed and compared to the standard structure made of two concentric foil coils. The experimental validation is made with short-circuit tests of an MFT fed by a low-level square voltage source at several kHz, which can provide the necessary high current. [ABSTRACT FROM AUTHOR]

This paper explores the effects and impacts of the metallurgical process of quenching on grain-oriented strips of electrical steel. Experimental findings reveal that quenching resulted in increased hardness and an increased Young's modulus. An analysis of the material structure post-quenching indicates significant alterations in grain spacing and reduced height differences between grains. However, the magnetic properties of the steel deteriorated following quenching. [ABSTRACT FROM AUTHOR]

The production of grain-oriented, electrical steel consists of a series of processes that lead to a product with superior magnetic properties used in transformers due to the low core loss. The unique properties are gained during the process of secondary recrystallization and abnormal grain growth. The abnormal grain growth occurs during a process of special thermal treatment with careful control over the heating rate, pressure, and type of gas used as atmospheric pressure during the process. The process of thermal treatment is known as high-temperature annealing. Investigating of developing the process hardware is crucially important to sustain energy-efficient processes and to maintain excellent final product properties. This research presents an overview of the technology of high-temperature coil annealing (HTCA) furnaces used at Cogent Power Orb, UK. The research focuses on some specific details of running, managing, and controlling the operation of the HTCA furnaces during the annealing process. The research provides energy analysis of the annealing process at Cogent Power Orb. Different factors were examined to identify the main factors that contribute to the high energy consumption. Actual data were collected from the annealing furnace control system. The raw data were processed and analyzed carefully to examine different factors, namely, steel charge weight, furnace on-time, and furnace heating elements. The study focused then on one specific factor, namely, annealing cycle time, and investigated further the way that this factor affects the process energy consumption. It was found that one of the main reasons for the long cycle duration and the high energy consumption is the failure of the heating elements during the cycle. The research discussed the area of improvements in the process hardware with a particular focus on the furnace design and the potential of introducing convection currents to overcome failure in the heating elements and thus reduce the process on time.

Ferroelectric (Hf,Zr)O2 thin films have attracted increased interest from the ferroelectrics community and the semiconductor industry due to their ability to exhibit ferroelectricity at nanoscale dimensions. The properties and performance of the ferroelectric (Hf,Zr)O2 films generally depend on various factors such as surface energy (e.g., through grain size or thickness), defects (e.g., through dopants, oxygen vacancies, or impurities), electrodes, interface quality, and preferred crystallographic orientation (also known as crystallographic texture or simply texture) of grains and/or domains. Although some factors affecting properties and performance have been studied extensively, the effects of texture on the material properties are still not understood. Here, the influence of texture of the bottom electrode and Hf0.5Zr0.5O2 (HZO) films on properties and performance is reported. The uniqueness of this work is the use of a consistent deposition process known as Sequential, No-Atmosphere Processing (SNAP) that produces films with different preferred orientations yet minimal other differences. The results shown in this study provide both new insight on the importance of the bottom electrode texture and new fundamental processing-structure–property relationships for the HZO films. [ABSTRACT FROM AUTHOR]

Ferroelectric (Hf,Zr)O2 thin films have attracted increased interest from the ferroelectrics community and the semiconductor industry due to their ability to exhibit ferroelectricity at nanoscale dimensions. The properties and performance of the ferroelectric (Hf,Zr)O2 films generally depend on various factors such as surface energy (e.g., through grain size or thickness), defects (e.g., through dopants, oxygen vacancies, or impurities), electrodes, interface quality, and preferred crystallographic orientation (also known as crystallographic texture or simply texture) of grains and/or domains. Although some factors affecting properties and performance have been studied extensively, the effects of texture on the material properties are still not understood. Here, the influence of texture of the bottom electrode and Hf0.5Zr0.5O2 (HZO) films on properties and performance is reported. The uniqueness of this work is the use of a consistent deposition process known as Sequential, No-Atmosphere Processing (SNAP) that produces films with different preferred orientations yet minimal other differences. The results shown in this study provide both new insight on the importance of the bottom electrode texture and new fundamental processing-structure–property relationships for the HZO films. [ABSTRACT FROM AUTHOR]

To examine the effect of mixed-frequency excitation conditions on the hysteresis and loss characteristics of ferromagnetic materials, this paper shows how to construct magnetic property test equipment for electrical steel using Epstein's square circle. Experiments were carried out to assess the hysteresis and loss properties of oriented silicon steel wafers under mixed-frequency sinusoidal operating conditions with different occupancy ratios. It used heterodyne extraction to investigate the effect of different occupancy ratios of industry and magnetization frequency on the hysteresis and loss characteristics of oriented silicon steel sheets. [ABSTRACT FROM AUTHOR]

Currently, many utility‐scale wind turbine generator original equipment manufacturers are dependent on imported rare earth permanent magnets, which are susceptible to market risks from cost instability. To lower the production costs of these generators and stay competitive in the market, several small wind manufacturers are pursuing continuous improvements to both generator design and manufacturing. However, traditional design and manufacturing methods have yielded marginal improvements in wind power performance. This work presents novel methods to redesign a baseline 15‐kW wind turbine generator with reduced rare‐earth permanent magnets by leveraging cutting‐edge three‐dimensional (3D) printed polymer‐bonded permanent magnets and steel. Symmetric, asymmetric, and multimaterial‐magnet parametrization methods are introduced for shape optimization. We extend the symmetric and asymmetric methods to the back iron in the stator to further investigate the impact and opportunities for performance improvements with lesser active materials. We employ a design‐of‐experiments approach with parametric computer‐aided design for shape generation and evaluate different designs by magneto‐thermal modeling and finite‐element analysis. We use adaptive sampling technique to identify better performing designs with lesser magnet mass, higher efficiency, and lower cogging torque when compared with the baseline generator. Asymmetric pole designs resulted in a magnet mass in the range of 4.77–5.37 kg, which was 27%–35% lighter than the baseline generator, suggesting that a new design freedom exists that can be enabled by advanced manufacturing, such as 3D printing. Shaping the back iron in the stator resulted in material savings in electrical steel of up to 14.62 kg, which was 20% lighter than the baseline stator. We conducted a structural analysis to evaluate an optimized asymmetric rotor design from the point of view of mechanical integrity and air‐gap stiffness. The magnetically optimal shape profile was shown as having a positive impact on the radial stiffness, and an optimal solution was discovered to reduce the structural mass by nearly 30 kg, which was 29% lighter than the baseline. [ABSTRACT FROM AUTHOR]

Effect of annealing stresses on the magnetic properties of non-oriented electrical steel has been studied. When the annealing stress increases from 2.5 to 4.5 MPa, the iron loss P1.0/400 of non-oriented electrical steel increases from 14.28 to 15.29 W/kg, the anisotropy index T raises from 17.0 to 22.0 pct, the magnetic induction B5000 decreases from 1.656 to 1.646 T. This is mainly due to the amount of MnS-containing precipitates increases with the increasing of the annealing stress. [ABSTRACT FROM AUTHOR]

At present, almost 50% of electrical power is consumed by motors. Thus, increasing the efficiency of motors is an important issue. To achieve more efficient operation, it is vital to improve the accuracy of input data for motor loss design. In this study, we focused on the iron loss of electromagnetic steels, which is assumed to account for a large proportion of motor losses, and examined whether the effect of stress on the iron loss and its frequency dependence could be predicted with high accuracy by machine learning. First, experimental iron loss data are obtained at flux densities of 0.1-1.7 T, frequencies of 50-3000 Hz, and applied stresses from 200 to 200 MPa. No significant deterioration in iron loss behavior is observed in specimens subjected to 3% and 10% pre-strain by tensile loading. These data show that the effect of stress on iron loss varies significantly depending on the excitation conditions. The complex iron loss behaviors are the result of interplay between magnetic wall movement and magnetic domain rotation during the magnetization process. As simple regression of the magnetization process is difficult, we apply three machine learning algorithms to the experimental dataset. The results show that the LightGBM algorithm produces the most accurate predictions of the experimental iron loss values. The contributions of the explanatory variables are found to be consistent with empirical knowledge. This study demonstrates the potential for machine learning to enable improve the accuracy of iron loss data input to motor loss design. [ABSTRACT FROM AUTHOR]