Amorphous Fe78Si9B13 Alloy Research Articles

Resonant Magnetoelectric Coupling of Fe-Si-B/Pb(Zr,Ti)O3 Laminated Composites with Surface Crystalline Layers.

The resonant magnetoelectric (ME) effect of Fe78Si9B13/Pb(Zr,Ti)O3 (FeSiB/PZT) composites with a surface-modified Fe78Si9B13 amorphous alloy has been studied. The surface-modified FeSiB can improve the ME coefficient at the resonant frequency by optimizing the magnetomechancial power conversion efficiency. The maximum ME coefficient of the surface-modified ribbons combined with soft PZT (PZT5) is two-thirds larger than that of the composites with fully amorphous ribbons. Meanwhile, the maximum value of the ME coefficient with surface-modified FeSiB ribbons and hard PZT (PZT8) is one-third higher compared with the fully amorphous composites. In addition, experimental results of magnetomechanical coupling properties of FeSiB/PZT composites with or without piezoelectric layers indicate that the power efficiency of the composites first decreases and then increases with the increase in the number of FeSiB layers. When the surface crystalline FeSiB ribbons are combined with a commercially available hard piezoelectric ceramic plate, the maximum magnetoelectric coupling coefficient of the ME composite reaches 5522 V/(Oe*cm), of which the electromechanical resonant frequency is 23.89 kHz.

The influence of the cluster connection modes on the soft magnetic properties in the Fe78Si9B13 amorphous ribbon

The structures and magnetic properties of Fe78Si9B13 amorphous ribbons were detected after annealing at different temperatures. Compared with the clusters in the FeB amorphous alloy, the second shell of BB coordination is replaced by SiB coordination in the clusters of the Fe78Si9B13 amorphous alloy. The interaction between Fe and B atoms is strengthened at a higher annealing temperature. Based on the Gaussian decomposition toward the splitting second peaks in g(r) curves, the shared connection modes of the clusters have been obtained. The main connection modes between the clusters of all the samples are the three-atom-shared connection and the one-atom-shared connection. With the increasing annealing temperature, the three-atom-shared connection is enhanced, and the one-atom-shared connections are weakened. Combined with the results of the magnetic hysteresis curves, it is found that the enhancement of the three-atom-shared connection is responsible for the increase of the saturation magnetization.

Corroded Fe78Si9B13 amorphous alloy as electrocatalyst for oxygen evolution reaction of water splitting

In this work, different amounts of FeOOH are in situ generated on an amorphous Fe78Si9B13 alloy ribbon by potentiostatic cathodic corrosion treatments for different time, including 0.5 h, 1 h, 2 h and 5 h, which are marked as the R-0.5h, R-1h, R-2h and R-5h, respectively. Afterwards, the corroded samples are investigated as electrocatalysts for the oxygen evolution reaction (OER) of water splitting in 1 M KOH. An appropriate amount of FeOOH not only provides more active sites, but also generates hydroxy1 radicals (OH˙) to greatly improve the efficiency of electronic transmission. However, when the surface of samples is covered by the thick and dense FeOOH layer, the catalytic reaction rate sharply decreases. The R-1h sample shows the best OER catalytic performances, which can achieve an overpotential of 356 mV at a current density of 10 mA cm−2 and the Tafel slope of 45 mV dec−1.

Nanocrystallization and magnetic property improvement of Fe78Si9B13 amorphous alloys induced by magnetic field assisted nanosecond pulsed laser

The influence of the magnetic field (514 and 1642 Gauss) assisted nanosecond pulsed laser processing on the structure and magnetic property of Fe78Si9B13 amorphous alloy is analyzed in this paper. The magnetic field causes the surface to splash obviously, which is related to the Lorentz force generated by the applied magnetic field and current. The magnetic field assisted nanosecond pulsed laser does not cause the Fe78Si9B13 amorphous alloy to crystallize significantly, and the XRD pattern still shows a typical amorphous diffuse scattering peak. However, the magnetic field can enhance the crystallization sensitivity of the Fe78Si9B13 amorphous alloy, and make more nanocrystals formed in the heat affected zone based on the SAXS and TEM data. Moreover, the magnetic property of the Fe78Si9B13 amorphous alloy is improved when the magnetic field is 514 Gauss. The main reason is that the transition from fcc structure units to bcc structure units occurs in the amorphous alloy. When the applied magnetic field intensity is larger (1642 Gauss), the saturation magnetization decreases. It can be explained by the B content in the residual amorphous matrix is too high with the precipitation of α-Fe(Si) nanocrystals, which is not conducive to the increase of the saturation magnetization.

Nanoporous Amorphous Fe78Si9B13 Alloys for Hydrogen Evolution in Alkaline Media

A serious of corrosion treatments are applied upon a melt-spun amorphous Fe78Si9B13 alloy to fabricate nanoporous structure for improving the alkaline hydrogen evolution reaction (HER) performances. The corrosion treatment produces a large number of nanopores on the surface, leading to remarkably improved HER performances. By corroding in 2M NaOH solution for 120 min, abundant pores with a diameter of about 50~100 nm were uniformly formed on the surface of the amorphous alloy. The nanoporous amorphous alloy can obtain a current density of 10 mA cm−2 at the overpotential of only 199 mV in 1M KOH environment, which is significantly reduced from that of the original melt-spun alloy of 386 mV under the same conditions. The corroded sample also shows excellent cycling performances. Microstructural study shows that after 1000 CV cycles the nanoscale columnar structure formed on the surface of the corroded sample are denser and larger than that of the melt-spun alloy, which effectively inhibit the increase range of the polarization resistance of the alloy.

Reduction and Immobilization of Movable Cu2+ Ions in Soils by Fe78Si9B13 Amorphous Alloy

The Fe-based amorphous alloy (Fe78Si9B13AP) is applied to the remediation of copper contaminated soil for the first time. The dynamic process of conversion of movable Cu to immobilized forms in the soil system is analyzed. In addition, the dynamic process of form transformation of Cu2+ ions in the soil system is analyzed. The morphology and phase composition of the reaction products are characterized by scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). Finally, the feasibility of recovering residual stabilizer particles and attached immobilized copper by the magnetic separation process is discussed. The results show that the apparent reaction rate constant of Fe79Si9B13AP with Cu2+ ions is higher than that of zero valent iron (ZVI) at all the experimental temperatures. According to the Arrhenius formula, the apparent activation energy of the reaction of Fe78Si9B13AP and ZVI with Cu2+ ions is 13.24 and 19.02 kJ/mol, respectively, which is controlled by the diffusion process. The lower apparent activation energy is one of the important reasons for the high reaction activity of Fe78Si9B13AP. After 7 days of reaction, a continuous extraction of the experimental soil shows that the main form of copper in the immobilized soil is Cu and copper combined with iron (hydroxide) oxide, and there is almost no soluble copper with a strong mobility, which effectively reduced the bioavailability of copper in the soil. The magnetic separation results of the treated soil show that the recovery rates of immobilized copper in Fe78Si9B13AP and soil are 47.23% and 21.56%, respectively, which reduced the content of iron and copper in the soil to a certain extent. The above experimental results show that Fe78Si9B13AP is a promising new material for the remediation of heavy metal contaminated soils, and provides more new references for the application of amorphous alloys in the field of remediation of water and soil contaminated by heavy metals and organic matter.

Numerical simulation of heat transfer and fluid flow during nanosecond pulsed laser processing of Fe78Si9B13 amorphous alloys

Nanosecond pulsed laser processing is a promising method to modify the microstructure of amorphous alloy. However, the heat and mass transfer mechanisms during processing are still unclear, which prevent regulating the microstructure precisely. In this study, a 3D heat transfer and flow coupling model is established to investigate the heat transfer and fluid flow behaviors, and their effects on the surface morphology and microstructure formation during the nanosecond pulsed laser processing of Fe78Si9B13 amorphous alloy. The physical processes such as melting and solidification, melt evaporation, melt convection and heat conduction, as well as the main driving forces such as surface tension, recoil pressure and gravity are taken into account in this model. The simulation morphology is in good agreement with the experimental results, indicating the validity of this numerical model. Based on simulation data analysis, it is found that the evolution mechanism of surface morphology is mainly related to the recoil pressure caused by evaporation and the Marangoni effect induced by the surface tension spatial gradient. Combined the temperature field analysis with experimental characterization, the formation mechanism of new amorphous phase in the molten zone (cooling rate at the order of 107 K/s) and the precipitation behavior of α-Fe(Si)/Fe-B phase nanocrystals in the heat-affected zone are clarified.

Effects of Milling Variables in Amorphous Phase Formation of Fe<sub>78</sub>Si<sub>9</sub>B<sub>13</sub> Alloy Produced by Mechanical Alloying

In this study, amorphous Fe78Si9B13 alloy was successfully synthesized by mechanical alloying (MA) of pure elemental powders which were milled under an argon gas atmosphere. Effects of milling time on the phase transformation, microstructure and morphological evolution were studied by X-ray diffraction (XRD), laser diffraction (Granulometry), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results showed that by increasing the milling time, the nanocrystalline and amorphous phase content increases and alloys with good properties are obtained at 100 h of milling.

Magnetic properties of a Fe-based amorphous alloy with stress gradient

The magnetic properties and domain structure of a Fe78Si9B13 amorphous alloy with a stress gradient from upper to the lower surface were investigated. We found that the magnetic properties of the samples vary significantly upon stress variation. Specifically, the magnetic anisotropy increases linearly with the maximum stress, whereas the coercivity, although higher than the one without stress, remains reasonably small. The phase contrast in magnetic force microscopy image and the fingerprint-like domains in magneto-optical Kerr microscopy images for ribbon surface with compressive stress demonstrate the presence of perpendicular anisotropy due to the magneto-elastic coupling. As a result, the compressive stress hinders the reversible magnetization vector rotation and makes the magnetization hard to be saturated. However, the stress causes no irreversible effects, neither on the domain wall movement nor on the magnetization rotation. Thus it is irrelevant to the coercivity. These results are different from the situation of the inhomogeneously distributed quenched-in stress enlarging the coercivity in Fe-based amorphous alloys.

Laser drilling process of Fe78Si9B13 amorphous alloy foil

The research on laser drilling of amorphous foils can promote the application of amorphous alloy in micro-machining. In this article, the effects of current, pulse width and defocusing amount on the quality of machined hole on Fe78Si9B13 amorphous alloy foils were analyzed by controlling the laser parameters. The experimental results showed that the hole diameter, remelting area (RMA) thickness and heat affected zone (HAZ) thickness increased obviously with the increase of current and pulse width. But high current caused serious erosion near the entrance of the hole and the taper of the machined holes increased with increasing pulse width. When the defocusing amount was 0, the hole diameter was the smallest and the forming quality of the machined hole was the best. Every parameter needs to be adjusted and coordinated to improve the quality of laser drilling.

Improved alkaline hydrogen evolution performance of a Fe78Si9B13 metallic glass electrocatalyst by ultrasonic vibrations

The electrocatalytic performance of a Fe78Si9B13 amorphous alloy toward alkaline hydrogen evolution reaction (HER) is enhanced by ultrasonic vibration (UV). The UV treatments slightly increase the crystallization enthalpy of the Fe78Si9B13 amorphous alloy from 141.54 J/g to 145.32 J/g, meanwhile a large number of micro-cracks, -holes and -chips are generated on the surface of the amorphous alloy. The overpotentials of the amorphous alloy treated with ultrasonic energy of 5000 J is only 173 mV at 10 mA cm−2 in 1.0 M KOH, which is reduced from 386 mV for the amorphous ribbon alloy at the same conditions. Moreover, the UV treated amorphous alloys also show better HER cycling performance comparing with those of the amorphous alloy without UV treatment. After 1000 CVs, it only needs 127 mV to reach the current density of 10 mA cm−2 for the materials treated with 5000 J. After 1000 CVs cycling reaction, the UV treated amorphous alloy shows much enlarged specific area compared with that of the untreated amorphous alloy, which should be the reason for the improved cycling HER performance.

Ultrafast reductive dechlorination of carbon tetrachloride by amorphous Fe78Si9B13 alloy

Amorphous Fe78Si9B13 ribbons and zero-valent iron (ZVI) powder were used to remove carbon tetrachloride (CTC) in the neutral oxic environment. The amorphous Fe78Si9B13 ribbons showed significantly better dechlorination performance than the ZVI powder, and the CTC could be degraded nearly completely within 3 h. The recyclability of amorphous Fe78Si9B13 ribbons was investigated, and the results confirmed their effectiveness and stability to remove the CTC for at least ten times. Our work demonstrates the application potential of amorphous alloys as an alternative to ZVI in the dechlorination of chlorinated organic compounds, and can provide new ideas for designing efficient dechlorinating agent in the actual field groundwater remediation.

Fabrication of deep-narrow microgrooves by micro-EDM using rotary dentate disc foil electrodes in emulsion

To accelerate the renewal of working fluid in machining gaps, this paper proposed using a dentate disc foil electrode (DDFE) for rotary micro electrical discharge machining (micro-EDM) to fabricate deep-narrow microgrooves. The DDFEs were machined from 30 µm thick Fe78Si9B13 amorphous alloy foils through wire electrical discharge machining. Under different process parameters, a series of experiments for fabricating microgrooves were performed by micro-EDM using the DDFE in emulsion. The effects of applied voltage, machining modes, clockwise rotation speed of the DDFE, and machining depth on the microgroove width were investigated in detail. Furthermore, the morphologies and dimensions of the microgrooves were characterized using a laser scanning confocal microscope and scanning electron microscope. The experimental results indicate that when the applied voltage U was 60 V, the DDFE clockwise rotation speed n was 3000 r min−1, the machining depth H was equal to the tooth height of 500 µm, the supply direction of the working fluid was right yet opposite to the the workpiece feed direction, a stable and fast micro-EDM process was achieved and a deep-narrow microgroove of width approximately 78 µm and aspect ratio 6.4 was obtained. With the optimized process parameters, array microgroove structures and column microstructures were fabricated successfully on #304 stainless steel workpieces.

Disordered Atomic Packing Structure of Metallic Glass: Toward Ultrafast Hydroxyl Radicals Production Rate and Strong Electron Transfer Ability in Catalytic Performance

Developing new functional applications of metallic glasses in catalysis is an active and pivotal topic for materials science as well as novel environmental catalysis processes. Compared to the crystalline materials with highly ordered atomic packing, metallic glass has a simply disordered atomic structure. Recent reports have demonstrated that the metallic glasses are indeed having many superiorly catalytic properties, yet the understanding of the mechanism is insufficient. In this work, the structural relaxation (α‐relaxation) by annealing in an amorphous Fe78Si9B13 alloy is studied for unraveling the catalytic mechanism at the atomic scale. The volume fractions of the crystalline structures, such as α‐Fe, Fe2Si, and Fe2B, in the as‐received and annealed metallic glasses are fully characterized. It is found that the randomly atomic packing structure with weak atomic bonding in the as‐received metallic glass has an efficient electron transfer capability, presenting advanced superiorities in the aspects of production rate of hydroxyl radicals (•OH), dye degradation rate (k), and essential degradation ability (KSA) for water treatment. The discovery of this critically important work unveils why using metallic glasses as catalysts has higher reactivity than the crystalline materials, and more importantly, it provides new research opportunities into the study of synthetic catalysts.

The relationship between atomic structure and magnetic property of amorphous Fe78Si9B13 alloy at different pressures

The structural and magnetic property of amorphous Fe78Si9B13 alloy at different pressures up to 282.1GPa were investigated by ab initio molecular dynamics simulations. With the pressure increasing, the structural evolution of amorphous Fe78Si9B13 alloy can be approximately divided into three regions, and the reduction of the interatomic distance leads to the exponential decrease of the average magnetic moment per Fe atom. Further, to establish the relationship between structure and atomic magnetic moment at a constant pressure, we focus on two types of polyhedra centered by Fe atoms in amorphous Fe78Si9B13 alloy at 0.0GPa. The result shows that the magnetic moment of central Fe atom is also influenced by the chemical composition besides the interatomic distance. For central Fe atom, more surrounding Fe atoms correspond to a larger magnetic moment, while the surrounding Si atoms is not conducive to the magnetic moment.

Ultra-sustainable Fe78Si9B13 metallic glass as a catalyst for activation of persulfate on methylene blue degradation under UV-Vis light.

Stability and reusability are important characteristics of advanced catalysts for wastewater treatment. In this work, for the first time, sulfate radicals (SO4∙−) with a high oxidative potential (Eo = 2.5–3.1 V) were successfully activated from persulfate by a Fe78Si9B13 metallic glass. This alloy exhibited a superior surface stability and reusability while activating persulfate as indicated by it being used for 30 times while maintaining an acceptable methylene blue (MB) degradation rate. The produced SiO2 layer on the ribbon surface expanded strongly from the fresh use to the 20th use, providing stable protection of the buried Fe. MB degradation and kinetic study revealed 100% of the dye degradation with a kinetic rate k = 0.640 within 20 min under rational parameter control. The dominant reactive species for dye molecule decomposition in the first 10 min of the reaction was hydroxyl radicals (∙OH, Eo = 2.7 V) and in the last 10 min was sulfate radicals (SO4∙−), respectively. Empirical operating variables for dye degradation in this work were under catalyst dosage 0.5 g/L, light irradiation 7.7 μW/cm2, and persulfate concentration 1.0 mmol/L. The amorphous Fe78Si9B13 alloy in this work will open a new gate for wastewater remediation.

Crystallization in Fe- and Co-Based Amorphous Alloys Studied by In-Situ X-Ray Diffraction

The amorphous alloys, Fe80Si20, Fe78Si9B13, and Fe4Co67Mo1.5Si16.5B11, were prepared by the spinning method in pure argon. The crystallization behaviors of the three amorphous alloys were researched by in-situ X-ray diffraction (XRD), and the crystallization activation energy was calculated, based on the results of differential scanning calorimetry. The crystallization mechanism of the Fe- and Co-based alloys was analyzed, based on the experimental data. The transformation kinetics was described in terms of Johnson–Mehl–Avrami kinetics, except that the Avrami exponent of the Fe78Si9B13 amorphous alloy annealed at 753 K (480 °C) was 4.12; the obtained values for the overall Avrami exponents of the other three amorphous alloys were below 1, as usually found for the Fe-Si amorphous alloys.

Amorphous Fe78Si9B13 alloy: An efficient and reusable photo-enhanced Fenton-like catalyst in degradation of cibacron brilliant red 3B-A dye under UV–vis light

The development of new functional applications of amorphous alloy is an active and challenging topic. In this work, amorphous Fe78Si9B13 alloy, a photo-enhanced Fenton-like catalyst, exhibits excellent functional ability in degrading an azo dye. This study reports the dramatic performance gains achieved for photo-enhanced Fenton-like degradation of cibacron brilliant red 3B-A (BR3B-A) dye aqueous solutions, the reusability of amorphous Fe78Si9B13 alloy ribbon catalysts, and the reaction kinetics (k) of the process. The individual and synthetical effects of the various reaction parameters are investigated by employing an orthogonal matrix (L16(45)) experimental methodology. The investigation evaluates the impact of these parameters on the degradation process, in order to demonstrate that UV–vis light could continuously induce hydroxyl radicals (OH) to be generated in the dye aqueous solution and significantly enhance the rate of dye degradation and mineralization. The experimental results show that nearly 100% color removal is achieved within 5min under conditions of 2.0g/L Fe78Si9B13 ribbons, 0.5M H2O2 and pH 2. UV–vis light intensity ranging from 0 to 7.7μW/cm2 enhances a dramatic improvement in color removal from 78% at 200min to 98% at 60min and an improvement in the reaction kinetics (k) from 0.0413at 0μW/cm2 of light irradiation to 0.2901 at 7.7μW/cm2 of light irradiation under conditions of 2.0g/L Fe78Si9B13 ribbons, 0.5M H2O2 and natural pH 6.45. The production of OH is investigated by adding tertiary butanol, resulting in a sharp decrease of dye color removal. Structural characterizations of as-received amorphous Fe78Si9B13 ribbons and of recycled Fe78Si9B13 ribbons are also investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), UV–vis diffuse reflectance spectrophotometers (UV–vis DRS), scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS); the results reveal a slight decay of the reused Fe78Si9B13 ribbons, along with a gradual precipitation of crystallized α-Fe, iron oxide and SiO2 on the ribbon surface over the few cycles of usage.

Core Losses Separation of Amorphous Alloy Core

In this paper, the core losses of Fe80Si9B11, Fe78Si9B13 amorphous alloy cores were separated to investigate the behaviors of hysteresis loss, eddy current loss and additional loss in high frequency range. The results showed that the losses of amorphous alloy core were mainly composed of hysteresis loss in low frequency. With the increase of frequency, eddy current loss increased drastically compared with the hysteresis loss, the eddy current loss was greater than the hysteresis loss when the frequency was higher than 5 kHz and 6 kHz for amorphous alloy with the composition of Fe78Si9B13 and Fe80Si9B11, respectively. The eddy current loss proportion in total loss increased with the increment of frequency.

Influence of High-temperature Oxidation on Soft Magnetic Properties of Fe78Si9B13 Amorphous Alloy

Abstract The influence of high-temperature oxidation on soft magnetic properties of Fe78Si9B13 amorphous alloy was investigated using various analysis methods. The results reveal that a 10 μm thick iron oxide layer with high resistivity can be obtained on the surface of Fe78Si9B13 amorphous ribbons by high temperature oxidation treatment. It is found that the amorphous alloy magnetization becomes harder and the saturation induction density changes after the high-temperature oxidation. The saturation induction density value changes from Bs=1.42∼1.46 T without chemical oxidation, to Bs=1.29∼1.38 T after high-temperature oxidation. The factors which have a great effect on the magnetization difficulties of the amorphous ribbons were discussed.