Magnetic Properties Of Amorphous Ribbons Research Articles

Effect of heat treatment on the properties of amorphous ribbons in acoustic magnetic tags

Taking Fe–Ni–Co amorphous ribbons in acoustic magnetic tags as research object, the microstructure, composition and crystallization temperature of amorphous ribbons were analyzed by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The manufacturing process and parameters (annealing temperature, tension and speed) of amorphous ribbons were systematically regulated and analyzed, including the influence on soft magnetic properties of amorphous ribbons by molding process. It indicates that non-magnetic annealing temperature (Ta) remains unchanged, the first magnetic annealing temperature (Tma1) is relatively higher, while second annealing temperature (Tma2), tension and speed are comparatively lower, amorphous ribbons emerge strong sensitivity and high reliability of soft magnetic properties. Meanwhile, combined with the actual experiment and orthogonal test analogy results, the best molding process parameters of amorphous ribbons are obtained: Ta, Tma1 and Tma2 are 375 °C, 315 °C and 255 °C respectively, tension is 8 N and speed is 4 m/min. In addition, the response demonstration of process is carried out under the condition that bias field value is 318.31 A/m and 366.06 A/m. The resonance frequencies of amorphous ribbons are 59.15 kHz and 58.55 kHz respectively, alongside a maximum vibration amplitude is 81, with the weakest and strongest response distance between transmitter and receiver are measured to be 150 cm and 160 cm, which are in line with the actual production process, indicating that the manufacturing process can be optimized to improve the production efficiency and service characteristics of acoustic magnetic tags.

Revealing the effects of cooling rate on soft magnetic properties of (Fe0·9Co0·1)86Ni1B13 amorphous alloy

Cooling rate is the key factor affecting soft magnetic properties of amorphous ribbons. So, is the faster the cooling rate conducive to better soft magnetic performance as theoretical hypotheses? The uncertainty of the debate on this issue in practical application motivates the present work. (Fe0.9Co0.1)86Ni1B13 amorphous ribbons with different thicknesses were prepared by deliberately varying the cooling rate. It was found that the amorphous ribbon prepared at a lower cooling rate exhibits better soft magnetic properties than the one prepared at a higher cooling rate. The reasons behind the improvement of the soft magnetic properties of amorphous ribbons were investigated in this work. The results prove that cooling rate strongly affect the surface morphology and residual stress of amorphous ribbons and thus the magnetic structure and properties of amorphous ribbons. On the premise of ensuring the formation of amorphous structure, high surface quality and low defects density of the ribbon prepared at low cooling rate promise candidates for the potential application in electric devices rather than the ribbons prepared at a high cooling rate.

Analysis of the Thermal and Magnetic Properties of Amorphous Ribbons of Fe_{61}Co_{10}B_{20}Y_8Me_1 (where Me~=~W, Zr, Nb, Mo)

Analysis of the Thermal and Magnetic Properties of Amorphous Ribbons of Fe_{61}Co_{10}B_{20}Y_8Me_1 (where Me~=~W, Zr, Nb, Mo)

An investigation into the effect of isothermal annealing on the structure (XRD), microstructure (SEM, TEM) and magnetic properties of amorphous ribbons and bulk amorphous plates

Abstract Test samples of the alloy Fe61Co10Y8W1B20 were fabricated in the form of both amorphous ribbons and bulk amor-phous plates. The structure, microstructure and magnetic properties of samples in the as-quenched state and after annealing were investigated. The aim of the paper is to show the effect of the thermal treatment on the structural changes occurring in the amorphous state. The thermal treatment, performed at well below the crystallisation temperature, did not cause crystallisation. In the investigated amorphous alloys it has been found that, after a specific thermal treatment, structural relaxation occurs in the presence of structural defects, such as quasidislocational dipoles. Also, supporting the microscopy investigations with measurements of the magnetic properties can be extremely beneficial for facilitating description of the real structure and properties of the amorphous alloys; further, this testing combination offers the possibility for designing the optimal application parameters for an alloy.

Magnetoinductance Effect in Co<sub>67</sub>Fe<sub>4</sub>Si<sub>14.5</sub>B<sub>14.5</sub> Amorphous Ribbons Annealed With Different Orientation Magnetic Fields

Magnetoinductance (MI) elements were constructed by winding a single coil on Co67Fe4Si14.5B14.5 amorphous ribbons fabricated by a single-roller melt-spinning technique. The effect of annealing methods on magnetic properties of amorphous ribbons was investigated. It was found that saturation magnetization, coercive force, and effective permeability of Co-amorphous ribbons were further improved by applying a magnetic field during annealing process. MI effect was evaluated by measuring the inductance under the magnetic field along the axis of MI elements. Experimental results showed that MI effect exhibited a characteristic of single peak curve and decreased with external magnetic fields regardless of the annealing methods. Although MI effect also decreased with frequency, the effect of frequency on MI effect was quite different for amorphous ribbons annealed with different processes. At the low frequency of 100 Hz, both the maximum inductance of $\sim 3.5\times 10^{-4}$ H and maximum magnetic field sensitivity of $\sim 37$ %/(A/m) belonged to MI elements with the ribbons annealed with the longitudinal magnetic field (LF). But at higher frequencies like 200 kHz, the annealing treatment LF was unexpectedly deteriorated to MI effect and the inductance and sensitivity of MI elements with the ribbons annealed longitudinal magnetic fields were even lower than those of MI elements with the as-quenched amorphous ribbons. By applying a transverse magnetic field during annealing process for amorphous ribbons, MI effect was always improved at all testing frequencies. The results were analyzed in terms of magnetic properties and magnetization process.

Thermal Stability, Mechanical Properties and Magnetic Properties of Fe-based Amorphous Ribbons with the Addition of Mo and Nb

The metallic glass ribbons of <TEX>$[(Fe_xCo_{1-x})_{0.75}B_{0.2}Si_{0.05}</TEX><TEX>]</TEX><TEX>_{96}Mo_4$</TEX> (x = 0, 0.3, 0.6, 0.9 at.%) and <TEX>$[(Fe_xCo_{1-x})_{0.75}B_{0.2}Si_{0.05}</TEX><TEX>]</TEX><TEX>_{96}Nb_4$</TEX> (x = 0, 0.3, 0.6, 0.9 at.%) were obtained by melt spinning with 25-30 <TEX>${\mu}m$</TEX> thickness. The thermal stability, mechanical properties and magnetic properties of Fe-Co-B-Si based systems were investigated. The values of thermal stability were measured using differential scanning calorimetry (DSC), including glass transition temperature (<TEX>$T_g$</TEX>), crystallization temperature (<TEX>$T_x$</TEX>) and supercooled liquid region (<TEX>${\Delta}T_x=T_x-T_g$</TEX>). These amorphous ribbons were identified as fully amorphous, using X-ray diffraction (XRD). The mechanical properties of Febased samples were measured by nano-indentation. Magnetic properties of the amorphous ribbons were measured by a vibrating sample magnetometer (VSM). The amorphous ribbons of <TEX>$[(Fe_xCo_{1-x</TEX><TEX>})_{0.75}B_{0.2}Si_{0.05}</TEX><TEX>]</TEX><TEX>_{96}Mo_4$</TEX> (x = 0, 0.3, 0.6, 0.9 at.%) and <TEX>$[(Fe_xCo_{1-x})_{0.75}B_{0.2}Si_{0.05}</TEX><TEX>]</TEX><TEX>_{96}Nb_4$</TEX> (x = 0, 0.3, 0.6, 0.9 at.%) exhibited soft magnetic properties with low coercive force (<TEX>$H_c$</TEX>) and high saturation magnetization (Ms).

The frequency dependence of demagnetizing factor of a Fe-based amorphous ribbon

The frequency dependence of total and internal demagnetizing factors has been investigated. A minimum of the demagnetizing factor at optimal frequency of magnetization reversal is revealed. The influence of the demagnetizing factor on the frequency dependence of magnetic properties of amorphous ribbon is studied.

The investigations of the amorphous metal properties in liquid state

A wide range of physical properties of liquid Co-based alloys has been investigated. The temperature dependencies of kinematic viscosity have shown to be nonmonotonic. The correlation between the viscosity and some magnetic properties of amorphous ribbons has been established. Higher viscosity of the melt leads to better magnetic properties: higher maximum permeability, lower coercive force. The re-melting leads to increasing of the magnetic properties of produced ribbons. The optimization of temperature regime of melt preparing before amorphization has been proposed.

Effects on the structural and magnetic properties of amorphous ribbons of (Co0.94Fe0.06)72.5Si12.5B15 caused by 4 MeV Cl2+ ion irradiation

The use of energetic ion irradiation to modify magnetic materials has attracted increasing interest in recent years. The possibility of patterning surfaces on these materials offers a wide range of potential applications particularly in technologies related to magnetic storage media, sensing devices and electromagnetic shielding materials. In this work, ultrasoft non-magnetostrictive (Co0.94Fe0.06)72.5Si12.5B15 amorphous ribbons, 50μm thick and 0.85mm wide, fabricated by the chilly block melt spinning technique are irradiated, in their amorphous state, by 4MeV Cl2+ ions with a fluence of 5×1013cm−2. The hysteresis properties of both irradiated and non-irradiated samples are characterized by means of a vibrating sample magnetometer while surface magnetic domain structure is observed by Bitter technique. The presence of an induced magnetic anisotropy in irradiated samples is ascribed to the local damage, caused by ion irradiation treatment, which results in modified coercive field and permeability of the samples. X-ray diffraction results are presented to confirm the amorphicity of the structure even after irradiation with ions.

On the dependence of magneto-elastic properties of amorphous ribbons on stresses induced by polishing and chemical etching

Abstract In this paper, the dependence of magnetic properties of amorphous ribbons and wires on aging is shown. Aging process is simulated by acid attack and thermal oxidation while coercive H c and remanence B r are measured by a stationary-coil magnetometer. The main conclusion is that H c and B r are stabilized after acid attack of H 2 SO 4 solution with pH 2 for 2 h and corresponding oxidation in 350 °C in free air for 2 h. Thus, the uncertainty of inductive sensors based on coercivity and remanence of amorphous ribbons and wires can be determined with respect to time.

Intercomparison of a single sheet tester for amorphous alloys by round robin measurements in Japan

A Japanese intercomparison of measurements of the magnetic properties of amorphous ribbons was carried out. Although the results for power loss are in fairly good agreement, the results for peak magnetic field strength and apparent power differ considerably.

The influence of quenching rate on magnetic properties of amorphous ribbons

Five sets of amorphous ribbons of the composition Fe73.5Cu1Nb3Si13.5B9 produced with different quenching rates (QR) were studied in order to verify the influence of the topological disorder on magnetic properties. For this purpose several magnetic methods were applied. Significant differences have been found between the results of magnetic disaccommodation He⋅Δμ/μ, pinning field Hp and stress dependence of the magnetic permeability μ/μ0(σ) of as-cast materials produced at different QR. The values of He⋅Δμ/μ and Hp are directly proportional to the disorder degree of the samples. The μ/μ0(σ) curves display broad maxima, which are found to be related to the quenched-in stresses. In contrast with these results, no significant effects of the amorphous structure on the Curie temperature and Mössbauer spectra were found, because other parameters are dominating.

アモルファスリボンの応力 磁化特性に及ぼす熱処理効果

The effects of heat treatment on the magnetic properties of amorphous ribbons under tensile stress are studied. In this study, we focus on two properties; coercive force and the stress-magnetization change due to tensile stress. The effects on these two properties of stress relaxation by heat treatment are demonstrated, and effects on them of samples heattreated under a magnetic field are also studied. The coercive force decreases at first when a small tensile stress is applied, but thereafter increases with the application of a larger stress. These properties can be explained by the change in the domain structure. The magnetization change due to an applied tensile stress under a constant magnetic field can be shown to be composed of two effects, namely reversible and irreversible magnetization change. The effects of heat treatment on these two changes are also investigated, and are also explained by the change in the domain structure.

Magnetic properties of amorphous ribbons after surface and heat treatment

The law of approach to ferromagnetic saturation for the amorphous Co 64Fe 14Si 11B 11 ribbons in the as-quenched state and thinned ribbons and after annealing is investigated. The transition from the 1/( μ 0 H) 2 law to the 1/ μ 0 H law after polishing the wheel surface is observed.

Effects of the Quenching Conditions on the Relaxation Enthalpy and on the Soft Magnetic Properties of Amorphous Ribbons*

Effects of the Quenching Conditions on the Relaxation Enthalpy and on the Soft Magnetic Properties of Amorphous Ribbons*

Anisotropy of losses in amorphous ribbons

The soft magnetic properties of amorphous ribbons are expected to be anistropic because of the shear deformation during the melt spinning procedure. In this paper the losses of an Fe 80B 14Si 6 amorphous ribbon were measured on stripes which were cut either parallel or perpendicular to the ribbon axis. The dependence of the losses as a function of peak induction and frequency suggests that there is an easy axis of magnetization parallel to the ribbon axis. After stress relief annealing this anisotropy is reduced. That is why this anisotropy is assumed to be due to internal stress introduced upon quenching.

Influence of continuous laser annealing on magnetic properties of amorphous ribbons: Connections with structural modifications and crystallization occurrence, as revealed by Mössbauer spectroscopy

In this paper the influence of continuous laser annealing on the magnetic properties and amorphous structure of Fe 40 Ni 40 P 14 B 6 ribbons is studied; an interpretation is given relating the measured magnetic behaviour with the structural aspects revealed by Mössbauer spectroscopy. The saturation induction, the magnetostriction, the initial permeability, the constant of magnetic anisotropy and the residual stress behaviour versus the annealing temperature are reported. The experimental results show that the continuous laser irradiation can be used to improve magnetic properties under appropriate conditions. In particular the average temperature of heating must not exceed 450 K. On the other hand, we show that the effects of continuous laser annealing are pre-eminently due to both the quenching stress relaxation and the formation of crystalline phases.

The deleterious effect of aluminium in Fe-B-Si-C amorphous ribbon

Adding aluminium to the change in amounts that could be introduced from carbon-reduced ferroboron can be extremely detrimental to the magnetic properties of amorphous ribbons. The degradation is attributed to the presence of a thin layer of crystalline material on the top surface of the as-cast ribbon, which produces a biaxial compressive stress in the bulk of the ribbon.

Magnetic properties of amorphous ribbon

The magnetic properties of transition-metal amorphous alloys are discussed, with emphasis on methods to increase the value of the saturation induction at room temperature, and on the factors that control the low-field magnetic properties that are important in most engineering applications.