Single Roller Melt-spinning Method Research Articles

FeSiBCuNbZr amorphous composites decorated with SiO2 and TiO2(B) (bronze phase TiO2) for efficient electromagnetic wave absorption

The application of Fe-based amorphous microspheres in high-performance electromagnetic wave absorbing materials is significantly limited by a single loss mechanism. Utilizing interfacial engineering and magnetic-dielectric synergistic effect is a viable approach to enhance microwave absorption. In this work, FeSiBCuNbZr amorphous microspheres were synthesized using single copper roller melt-spinning method and ball mill method. The finding reveals that the incorporation of SiO2 and TiO2(B) (bronze phase TiO2) shells notably enhances polarization loss and conductive loss. FeSiBCuNbZr@SiO2@TiO2(B) amorphous composites exhibited a minimum reflection loss value of −64.89 dB at a thickness of 2.17 mm and an effective absorption bandwidth (EAB) of 8.08 GHz covering 9–18 GHz at a thickness of 1.9 mm. The exceptional wave absorption performance is ascribed to the combined effect of magnetic loss in the FeSiBCuNbZr amorphous core and dielectric loss from the double-shell structure, while maintaining favorable impedance matching. This work provides a new core–shell FeSiBCuNbZr amorphous composites for efficient electromagnetic wave absorption.

Effects of rare-earth element Y content on the microstructure and properties of quinary Al–Ni–Zr–Co–Y high entropy metallic glasses

A series of quinary (Al1/4Ni1/4Zr1/4Co1/4)100-xYx (x = 16–28 at.%) high entropy metallic glass ribbons were successfully fabricated through the high-speed single roller melt-spinning method. The effects of rare-earth element yttrium content on the microstructure and performances of alloy ribbons were systematically investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), heat treatment, transmission electronic microscopy (TEM), atomic force microscopy (AFM) and electrochemical experiments. The microhardness of metallic ribbons was measured by Vickers hardness tester. Results show that the microstructure of the as-quenched alloy ribbons maintain the glassy state and the average microhardness value of each specimen can reach 488 HV0.1 or above. The surface morphologies of the as-spun ribbon samples exhibit the smooth surface with small roughness value of Ra = 0.115–0.150 nm. In the meantime, with the increase of Y content, the glass transition temperature can be detected in the DSC traces when Y content is over 22 at.%, and the crystallization onset temperature shifts to the lower temperature region, suggesting that the thermal stability of amorphous state in Al–Ni–Zr–Co–Y alloy ribbons has been weakened. The (Al1/4Ni1/4Zr1/4Co1/4)84Y16 alloy ribbons own the highest crystallization onset temperature (∼742 K). Adding appropriate yttrium element can enlarge the super-cooled liquid region and improve the glass-forming ability. In 3.5 wt% NaCl solution, the prepared alloy ribbons can maintain smaller corrosion current densities (∼10−8 A cm−2) than traditional Al-based amorphous alloys, 6061 Al alloy and other common structural steels. The X-ray photoelectron spectrometer results indicate that the passive film of equiatomic alloy ribbons is rich in oxides of Al, Zr, Co, and Y elements, which has excellent resistance to chloride ion attack. On the basis of all experimental results, (Al1/4Ni1/4Zr1/4Co1/4)84Y16 alloy ribbons can optimally combine outstanding corrosion resistance, superior thermal stability, and acceptable microhardness. The above research results lay a solid foundation for the composition development of high-performance high entropy metallic glasses.

Air surface crystallization with quenched-in Fe crystallites and associated magnetomechanical properties in Fe–Si–B amorphous ribbons

The effect of surface crystallization on the magnetomechanical properties is studied for amorphous ribbons with a nominal composition of Fe80Si9B11 that are prepared with the single roller melt-spinning method. Our results indicate that the magnetomechanical power efficiency of surface crystallization ribbons is twice as higher as that of its amorphous counterpart. The surface configuration for such ribbons has been investigated through a prism of microstructures and chemical compounds. The surface crystallization with quenched-in α-Fe(Si) crystallites is confirmed by means of x-ray diffraction measurements and the surface polishing process, inducing irregular in-plane domain patterns, which are observed by magneto-optical Kerr effect microscopy. The vibrational absorption peak for polymerized B–O bonds is observed by means of a Fourier transform infrared spectrometer, being ascribed to the presence of pre-precipitated boron atoms from the crystalline film, which is confirmed by x-ray photoelectron spectroscopy. The mechanism that enhances the magnetomechanical power conversion efficiency in FeSiB ribbons with quenched-in crystallites is quite different from the ones with annealing induced “surface-interior” configurations in the previous investigations.

Development of novel FeCo based amorphous FeCoBPSiCr alloy with high Bs of 1.71 T and high corrosion resistance

Metallic ribbons of different compositions were prepared using a single-roller melt-spinning method. The (Fe0.8Co0.2)83B11P4Si2 alloy without Cr showed both high saturation magnetic flux (Bs) of 1.78 T and high corrosion resistance, with a corrosion potential of −607 mV and a corrosion current density of 29 μA/cm2 compared to those of a conventional high-Bs Fe79B13.5Si5.5C2 amorphous alloy. The (Fe0.7Co0.3)82B11P4Si2Cr1 alloy with Cr also exhibited a high Bs of 1.71 T and high corrosion resistance at the same level as that of a conventional Fe73B11Si11C3Cr2 amorphous alloy. The (Fe0.7Co0.3)82B11P4Si2Cr1 alloy showed a corrosion potential of −509 mV and a corrosion current density of 18 μA/cm2. Furthermore, the (Fe0.7Co0.3)82B11P4Si2Cr1 alloys exhibited a high amorphous forming ability because of a single amorphous phase in the metallic ribbon at a thickness of >60 μm. Based on these results, the (Fe0.7Co0.3)82B11P4Si2Cr1 amorphous alloy with the possibility of powderization was confirmed to be a suitable material for the magnetic core that is widely used in metallic inductive components.

Effects of adding B element on amorphous forming ability, magnetic properties, and mechanical properties of FePBCCu alloy

Fe-based amorphous alloys are widely used in power electronics fields such as transformers and reactors due to their low coercivity, high permeability and low loss. However, the relatively low saturation magnetization (<i>B</i><sub>s</sub>) limits their further applications. Generally speaking, the adjustable magnetic Fe content as an effective strategy can ameliorate the magnetic properties, and the higher the Fe content, the higher the obtained <i>B</i><sub>s</sub> is, but the decrease of the corresponding non-magnetic element content will result in the drop of the ability of alloys to form amorphous phase, leading to the deterioration of the magnetic softness and bending ductility of nanocrystalline alloys. To address this critical issue, in this work, based on the metal-metalloid hybridization, the FePBCCu amorphous ribbons, each with a thickness of ~25 μm, are prepared by the single-roller melt spinning method via 7% (atomic percent) B substitution for P, and the effects of B element addition on the ability to form amorphous phase, magnetic properties and mechanical properties of ribbons are investigated. Thermodynamic behavior shows that the addition of small quantities of B element can reduce the structural heterogeneity of alloy and the crystallization driving force as well, thus effectively improving the thermal stability of the amorphous matrix. The melting and solidification curves show that the addition of B can promote alloy to approach to the eutectic composition, and there is a large degree of undercooling. As a result, the critical thickness of ribbons increases from ~21 μm for B-free alloy to ~30 μm for B-added alloy due to the micro-alloying effect. The addition of B increases the effective magnetic moment of magnetic atoms in alloy, resulting in the increase of the saturation magnetization. Furthermore, the results of nanoindentation tests show that the modulus value of the B-added alloy decreases greatlyr and fluctuates in a smaller range than that of the B-free alloy, which is closely associated with the structural uniformity of the alloy.

Bioactivity and <italic>in</italic> <italic>vitro</italic> degradation behavior of MgZnCa thin-film metallic glass

<p indent="0mm">Magnetron sputtering was used to prepare MgZnCa thin-film metallic glass (MG), and a single roller melt-spinning method was used to prepare amorphous MgZnCa ribbon. Potential polarization curves of MgZnCa amorphous ribbon and bulk high-purity magnesium (HP Mg) in simulated body fluids were compared using electrochemical tests. The corrosion resistance of MgZnCa MG is found to be significantly better than that of HP Mg, which is mainly attributed to its higher corrosion potential and lower corrosion current density. Immersion experiments, hydrogen evolution experiments, X-ray diffraction, Raman spectroscopy, and scanning electron microscopy were used to analyze the structure and composition of MgZnCa thin-film MG (TFMG) before and after corrosion, showing that the release rate of hydrogen was the fastest in the first hour, with active magnesium and calcium on the film’s surface preferentially dissolved. Furthermore, the appearance of a zinc-rich phase in the corrosion film and the increase in local pH promotes the precipitation of phosphate, which can improve the corrosion resistance of MgZnCa MG. <italic>In</italic> <italic>vitro</italic> experiments show that the 25% concentration extract obtained after soaking the MgZnCa MG has higher cell viability and lower apoptosis rate than the control medium, indicating that the MgZnCa MG is biocompatible. Therefore, with excellent corrosion resistance and biocompatibility, MgZnCa MG can be used as bioactive coatings on the surface of biologically inert materials.

Effect of the substitution of Si for B on thermal stability, magnetic properties and corrosion resistance in novel Fe-rich amorphous soft magnetic alloy

Soft magnetic alloy Fe83.3SixB16-xCu0.7 (x = 0, 1, 2, 3 and 4) ribbons were produced by the single roller melt spinning method. The Si content dependence of magnetic properties and corrosion resistance was investigated. Appropriate addition of Si is effective to the improvement of thermal stability, soft magnetic properties and corrosion resistance in this alloy system. Excellent soft magnetic properties with low coercivity 3.1 A/m and high magnetic flux density 1.66 T can be obtained when x = 1 annealed at 365 °C for 10 min. Compared with the Si-free ribbon, the corrosion resistance of the x = 1 alloy ribbon is also improved. The X-ray photoelectron spectroscopy (XPS) indicates that the formation of an SiO2-enriched passive film is mainly responsible for the high corrosion resistance of Si-containing (x = 1) alloy in 3.5 wt% NaCl solution. Low cost of raw materials, high thermal stability, good soft magnetic properties as well as excellent corrosion resistance make this alloy a promising candidate for future application.

NGHIÊN CỨU BIỂU HIỆN TỚI HẠN TRONG CÁC BĂNG HỢP KIM Fe88Co2Zr7B2Cu1

In this work, we investigated the critical behavior of Fe88Co2Zr7B2Cu1 alloy ribbons prepared using a single-roller melt-spinning method. X-ray diffraction analysis shows that the alloy is almost amorphous. This alloy undergoes a second-order ferromagnetic-paramagnetic (FM-PM) phase transition at room temperature (Curie temperature TC = 296 K). To investigate the nature of the FM-PM phase transition near the TC for the alloy, we performed a critical-exponent study. Based on modified Arrott plots, the Kouvel-Fisher method, and Widom’s scaling relation, a set of critical parameters were determined. The critical parameters are β = 0.545 ± 0.041 and γ = 1.109 ± 0.018 obtained from the modified Arrott plots; β = 0.547 ± 0.005 and γ = 1.105 ± 0.016 from the Kouvel-Fisher method, and d = 3.035 ± 0.059 from Widom’s scaling relation. These values are close to those expected for the mean-field model, revealing long-range FM interactions.

Effect of melt cooling rate on glass transition kinetics and structural relaxation of Vit1 metallic glass

The thin ribbons and the bulk cylindrical rods with diameters of 2 mm and 10 mm of the Vit1 metallic glass (MG) were prepared by the single roller melt spinning method and the copper mold injection casting method, respectively. The cooling rates of the samples during melt solidification were evaluated. The glass transition behaviors of three groups of MG samples with different solidification cooling rates were studied by differential scanning calorimetry (DSC) at different heating rates. The effects of melt cooling rate on the glass transition kinetic parameters such as apparent activation energy (E) and fragility parameter (m) of the Vit1 MG were studied using the Kissinger and the Vogel-Fulcher-Tammann (VFT) equations. Additionally, the structural relaxation enthalpy (ΔHrel) of three groups of MG samples was quantitatively analyzed by DSC through multi-step temperature rise and fall measurements. Results show that the melt cooling rate (R) has a significant effect on the glass transition kinetics and the structural relaxation of the Vit1 MG. As R decreases in the order of magnitude, the glass transition temperature (Tg), E, m, and ΔHrel of the Vit1 MG gradually decreases. Furthermore, in the range of the experimental cooling rates, E, m, and ΔHrel all have an approximately linear relationship with lgR.

Fast Degradation of Azo Dyes by Using Cu-based Metallic Glasses

Wastewater containing azo dye has become a main harm in water pollution. Therefore, development of environment friendly materials with efficient purifying capacity seized more and more attention of people devoting to dye wastewater processing. On the other hand, advancement of metallic glasses in degrading organic water contaminant has also received wide concern. Cu-based amorphous alloy has excellent corrosion resistance and good stability in the process of degradation of azo dyes In the present thesis, single roller melt-spinning method Cu-Zr-Al-Y metallic glasses is applied so as to investigate degradation of azo dye Direct Blue in acid and alkaline solution. It is concluded that when the value of it is 2, 25μm ~ 30μm thick stripes of non-crystalline structures will be formed. With variation of the pH, rate of degradation will also change. The degradation rate in acidic solution is higher than that in alkaline and neutral solution. This is due to the fact that Azo bond and Cu-based amorphous alloy in dye molecule requires quite low activation energy to react, which makes degradation easier to proceed and thus macroscopic decoloration is also quickened. After the treatment of wastewater, white corrosion products will be produced on the surface of amorphous strip. It will affect the degradation effect.

Preparation and magnetocaloric properties of amorphousFe-Zr-B-Dy alloys

Amorphous magnetocaloric alloys can achieve large magnetic refrigeration capacity in a wide temperature range. Iron-based amorphous magnetocaloric alloys are widely concerned because of their near room-temperature magnetic entropy change range and low cost. In this paper, a series of Fe89− x Zr7B4Dy x ( x= 1, 2, 3, 4) amorphous alloys have been successfully prepared by the single roller melt-spinning method. The structures, thermodynamic parameters, and magnetocaloric properties have been systematically tested and analyzed for the alloys. With the increase of Dy content, the glass forming ability of the alloy was increased, and the Curie temperature got increased from 296 to 334 K. The maximum entropy change of Fe85Zr7B4Dy4 alloy is 2.45 J K−1 kg−1 and the refrigeration capacity is 235 J kg−1 at 3 T applied magnetic field. Compared with the ternary Fe-Zr-B system, the peak value of magnetic entropy change is increased by more than 60% under same magnetic field. The raw material of the amorphous alloy has low cost, and its Curie temperature can be adjusted with the change of composition. The Curie temperature is far lower than the glass transition temperature, which can ensure the structural stability of the material in the application process, and it is expected to become a magnetic refrigeration working medium near room temperature.

Effect of Ce and La Substitution on the Microstructure and Magnetic Properties of Hot-deformed Nd-Fe-B Magnets

Nd in hot-deformed Nd-Fe-B magnets was partially substituted by Ce and La for the purpose of reducing the materials cost and balancing the utilization of rare earth resources. Initial melt-spun ribbons with the nominal compositions of (NdSUB1-x/SUBMSUBx/SUB)SUB13.6/SUBFebalBSUB5.6/SUBGaSUB0.6/SUBCoSUB6.6/SUB (x = 0, x = 0.2/M=Ce, x = 0.3/M=Ce, Ce+La, wt.%) were prepared by a single-roller melt-spinning method, and pulverized into powders. The powders were then hot-pressed at 973 K under 100 MPa, and deformed at 973 K until 75 % of height reduction was achieved. The magnetic properties of hot-deformed magnets were decreased with the substitution of Ce for Nd. In addition, simultaneous substitution of Ce and La for Nd resulted in much lower magnetic properties. This tendency was almost the same as initial melt-spun powders. The deterioration on magnetic properties by substation of Ce and La for Nd in hot-deformed Nd-Fe-B magnets could be attributed to not only inferior intrinsic properties of (Ce/La)₂FeSUB14/SUBB to Nd₂FeSUB14/SUBB phase but also the effect of Ce/La substitution on microstructure such as density and grain alignment during hot-deformation. Although the magnetic properties were deteriorated by substitution of Ce and La for Nd in hot-deformed Nd-Fe-B magnets, the cost performance was largely enhanced from 2.32 to 2.62 MGOe×kg/$ by 13 % when increasing the content of Ce substituted for Nd from 0 to 0.3 wt.%.

Fe-B-Nb-P Nanocrystalline Alloy With High Amorphous Forming Ability for Fabricating the Powder

The effect of B and P content on the amorphous forming ability (AFA), thermal stability, amorphous stability, and structural behavior was investigated in Fe-B-Nb-P alloys using metallic ribbons produced by a single-roller melt-spinning method. The maximum thickness, $t_{\mathbf {max}}$ , indicating AFA of Fe84-{x}B9Nb7Px ( ${x} =0$ –4), increased from 19.5 to $68.7~\mu \text{m}$ . The alloys exhibited two exothermic peaks to have resulted from the formation of bcc $\alpha $ -Fe and borides, respectively. The Fe84-{x}B9Nb7Px ( ${x} =0$ –3) alloys with the wide interval between two exothermic peaks exhibited the high thermal stability compared to the commercialized composition of Fe73.5Si13.5B9Nb3Cu1. The wide range between the glass transition temperature and crystallization temperature means the super-cooled liquid region, leading to obtain the high stable amorphous phase. The super-cooled liquid region was observed in Fe81-{y}B9+{y}Nb7P3 ( ${y} =0$ –2) alloys and the endothermic reaction of the super-cooled liquid region got larger by increasing B content. The $\alpha $ -Mn type structure was observed in Fe80B10Nb7P3 alloy annealed at 823 K, and it was considered to improve the amorphous stability. The Fe81B9Nb7P3 alloy with a high AFA of $68.7~\mu $ m exhibited excellent magnetic characteristics, $B_{s}$ of 1.51 T and $H_{c}$ of 4.7 A/m.

FeBNbP nanocrystalline alloy powder with high amorphous forming ability and high B s for magnetic core

The influence of P content on amorphous forming ability and the magnetic characteristics were investigated in the FeBNbP nanocrystalline alloys using metallic ribbons. The Fe84-xB9Nb7Px(x=0-3) and Fe80B10Nb7P3 nanocrystalline alloy metallic ribbons prepared by a single-roller melt-spinning method. The Fe84-xB9Nb7Px (x=0-3) and Fe80B10Nb7P3 nanocrystalline alloys annealed at 873-923 K consist of stable α-Fe grain formed in a residual amorphous phase, and the nanocrystal α-Fe grain showed the average diameter from 6.3 to 7.7 nm. The critical thickness of ribbons indicating amorphous forming ability was increased from 20 μm to 68.7 μm with Fe81B9Nb7P3 by increasing P content. The Fe81B9Nb7P3 alloy also exhibited a high saturation magnetic flux density, Bs, of 1.51 T. In addition, Fe81B9Nb7P3 alloy indicated a good magnetic softness with a low coercivity, Hc, of 4.8 A/m. The Fe80B10Nb7P3 alloy increasing B content succeeded to obtain the powder with precursor of a stable amorphous phase by rapid quenching gas atomization method.

Double magnetic entropy change peaks and high refrigerant capacity in Gd1-xHoxNi compounds in the melt-spun form

Gd1-xHoxNi melt-spun ribbons were fabricated by a single-roller melt spinning method. All the compounds crystallize in an orthorhombic CrB-type structure. The Curie temperature (TC) was tuned between 46 and 99 K by varying the concentration of Gd and Ho. A spin reorientation (SRO) transition is observed around 13 K. Different from TC, the SRO transition temperature is almost invariable for all compounds. Two peaks of magnetic entropy change (ΔSM) were found. One at the higher temperature range was originated from the paramagnet-ferromagnet phase transition and the other at the lower temperature range was caused by the SRO transition. The maximum of ΔSM around TC is almost same. The other maximum of ΔSM around SRO transition, however, had significantly positive relationship with x. It reached a maximum about 8.2 J kg−1 K−1 for x = 0.8. Thus double large ΔSM peaks were obtained in Gd1-xHoxNi melt-spun ribbons with the high Ho concentration. And the refrigerant capacity power reached a maximum of 622 J kg−1 for x = 0.6. Gd1-xHoxNi ribbons could be good candidate for magnetic refrigerant working in the low temperature especially near the liquid nitrogen temperature range.

Glass Forming Ability and Crystallization Kinetics of Cu-Zr-Al-(Y, Ag) Amorphous Alloy

Cu-Zr-Al-(Y, Ag) amorphous alloy ribbons of Cu50Zr42Al8, Cu46Zr47-xAl7Yx(x=2, 5), Cu43Zr42Al8Ag7, and Cu43Zr42Al8Ag5Y2 were prepared using the single roller melt-spinning method. The glass forming ability and non-isothermal crystallization behavior of the amorphous alloys were investigated by means of X-ray diffraction (XRD) and differential scanning calorimetry (DSC) in a continuous heating mode. The experimental results show that the glass forming ability and thermal stability of Cu-Zr-Al amorphous alloys are improved by adding minor amounts of Y and Ag, and the effect of Ag on the glass forming ability is more significant than that of Y. Compared to the Cu50Zr42Al8 alloy, the width of the supercooled liquid region of the Cu46Zr47-xAl7Yx(x = 2 and 5) alloys increased by 19 K and 30 K, respectively. The reduced glass transition temperature (Trg) and the parameter γ of the two alloys enhanced separately. Compared to the Cu50Zr42Al8 alloy, the Trg and γ values of both Cu43Zr42Al8Ag7 and Cu43Zr42Al8Ag5Y2 alloys enhanced noticeably up to 0.619, 0.417, and 0.609, 0.412, respectively. The crystallization activation energies of the amorphous alloys calculated by the Kissinger and Flynn Wall Ozawa equations increased with the addition of minor Y and Ag into the Cu50Zr42Al8 alloy. The addition of Y and Ag significantly improved the thermal stability of the Cu50Zr42Al8 amorphous alloy.

Effect of Ti on structure and soft magnetic properties of Si-rich Finemet-type nanocrystalline Fe73.5Cu1Nb3-xSi17.5B5Tix alloys

Fe73.5Cu1Nb3-xSi17.5B5Tix (x = 0, 1, 2, 3) amorphous alloys were prepared by the single roller melt spinning method. The effects of Ti substitution for Nb on the crystallization behavior, microstructure and soft magnetic properties were investigated. Compared to the previously reported Finemet alloy, the onset primary crystallization temperature Tx1 becomes lower which has dropped from 803K to 758K. The crystallization temperature interval ΔTx increases from 468K to 488K as the x increases from 0 to 3. However, the Curie temperature of amorphous phase shows a downward tendency with the increase of Ti content. Compared to the previously reported Finemet alloy, the μi increases obviously to more than 18,000 at x = 1, the Hc decreases from 0.59 Oe to 0.54 Oe. When Ti replaces Nb completely, the optimum annealing temperature range for precipitating single soft magnetic phase is enlarged, but the permeability at room- and high-temperature is deteriorated, the reason of which was also analysed.

The room temperature large magnetocaloric effects with a wide temperature span in Gd70Y30−xFex alloys

The Gd70Y30−xFex (x = 0, 10 and 20) ribbon alloys were prepared by single-roller melt spinning method. The results show that all samples are single phase and crystallize with a hexagonal structure. The magnetic entropy change at 5 T are 8.8, 8.1 and 5.7 J·kg−1·K−1 near the Curie temperature of 277 K, 283 K and 291 K for Gd70Y30−xFex alloys with x = 0, 10 and 20, respectively. Furthermore, the values of full width at half maximum and refrigeration capacity under applied field 5 T increase by 55% and 6% compared with pure Gd respectively. The obtained spontaneous magnetization and adiabatic temperature (Δ2T) are 238, 241, 197 emu/g and 4.0, 3.5, 2.4 K for samples with x = 0, 10, and 20, respectively. The Arrott plots and universal curve are employed to investigate the magnetic phase transition, showing all samples undergo a second order ferro-paramagnetic phase transition. The results indicate that Gd70Y30−xFex alloys with large magnetocaloric effect and wide temperature span are a good candidate for room temperature magnetic refrigeration.

Development of soft magnetic amorphous alloys with distinctly high Fe content

This paper reports on the preparation of Fe82.7-85.7Si2-4.9B9.2-11.2P1.5-2.7C0.8 soft magnetic amorphous alloys with a distinctly high Fe content of 93.5-95.5 wt.% by component design and composition adjustment. All alloys can be readily fabricated into completely amorphous ribbon samples with good surface quality by the single copper roller melt-spinning method. These alloys show good bending ductility and excellent magnetic properties after annealing, i.e., low coercivity ( H c) of 3.3-5.9 A/m, high permeability ( μ e) of 5000-10000 and high flux saturation density ( B s) of 1.63-1.66 T. The mechanism of the good glass forming ability (GFA) and soft-magnetic properties are explored. The amorphous alloys with the high Fe content comparable to that of the desired high Si alloy can be promising candidates for the potential application in electric devices.

The Influence of Annealing Temperature on Microstructure and Magnetic Properties of Fe74Co3Si8B10Al1Nb4 Amorphous Alloy Ribbons

Multi-component alloy ribbons with a composition of Fe74Co3Si8B10Al1Nb4 were prepared by a single roller melt-spinning method. The alloy had a fully amorphous structure, as determined by X-ray diffraction. The alloy ribbons were annealed for 10 min at temperatures of 350, 400, 450, 500, 550 and 600 oC, respectively. Differential scanning calorimetry curves indicated that the glass transition temperature (Tg) and the supercooled liquid range (ΔTx) of the amorphous alloy ribbon were about 494 oC and 43 oC, respectively. The ribbons showed soft magnetic properties, with a Curie temperature (Tc) at 284 oC, high saturation magnetization (Ms) of 1.18 T, and coercive force (Hc) of 33.66 A/m. In the present study, both saturation magnetization and coercive force of amorphous alloy ribbons increased with increasing the annealing temperature, due to precipitations and growth of α–Fe phase nanocrystals in the amorphous matrix. On the other hand, it was found that the coercive force of alloy ribbons reduced as a consequence of precipitations of Nb3Si phase if the annealing temperature reached 600 oC.