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Adding trace Ni elements and annealing in a magnetic field improves the soft magnetic properties of the Finemet. After changing the Ni content to control the composition of the alloy system and change the pitch of stripes of the magnetic domains, Fe73.5Si14.7B7.6Nb3Cu1Ni0.2 nanocrystalline ribbon with excellent soft magnetic properties was obtained. In this work, transverse magnetic field annealing (TA) was performed on Fe73.5Si14.7B7.6Nb3Cu1Ni0.2 nanocrystalline ribbon cores (NRCs), and the magnetic properties and magnetic domain structure were compared in detail with those after non-field annealing (NA), and the mechanism of the improvement of soft magnetic properties by TA was elucidated. The soft magnetic properties of the cores were adjusted by varying the Ni composition, annealing temperature, and magnetizing temperature. The experimental results show that the core loss (Ps) of the NRCs is reduced by 24.76% (100 kHz, high frequency) and the coercivity (Hc) is 0.854 A/m after 30 min of TA at 400°C compared to the NA sample. TA optimizes the soft magnetic performance of NRCs by optimizing the domain structure and broadening the size of the domain. These results can provide a good guide for optimizing the performance of NRCs with low Ps at high frequency. [ABSTRACT FROM AUTHOR]

The influence of precipitated nanophases on the mechanical properties of Fe-based amorphous nanocrystalline alloys is an urgent issue to be explored. Two amorphous nanocrystalline alloys, i.e., (Fe0.9Ni0.1)86B14 and (Fe0.7Ni0.3)86B14 containing nanophase of the body-centered cubic and face-centered cubic structures, respectively, were selected to investigate the effect of the structure and volume fraction of nanophase on their mechanical properties. The results of nanoindentation experiments and the calculation of the volume and size of the shear transition zone reveal that the two alloys show different mechanical properties. When the volume fraction of the nanophase in (Fe0.9Ni0.1)86B14 is larger than 50%, the elastic modulus is increased suddenly and the volume and size of the shear transition zone is decreased dramatically, while no dramatic change occurs in (Fe0.7Ni0.3)86B14. Moreover, it was found by using molecular dynamics simulations that the main reason for these abnormal mechanical properties is the change of cluster type in the system due to the incorporation of nanophases with different structures. [ABSTRACT FROM AUTHOR]

Metallic glasses (MGs) with unique disordered atomic stacking structures exhibit excellent catalytic performance in wastewater treatment. The catalytic degradation of Orange II (AO II) aqueous solutions by four CuZr-based MG ribbons under such processing parameters as pH values, the dosage of ribbons, and temperature was investigated in this paper. The catalytic performance of the MG ribbons was characterized by using the degradation efficiency of the dye wastewater. The phase constituent, surface morphology, and chemical valence state of elements on the surface of MG ribbons before and after use were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS), respectively. The results indicate that the Cu46Zr42Al7Y5 MG ribbon has the best catalytic performance among the Cu46Zr47-xAl7Yx (x = 0, 1, 3, 5) MGs in the degradation process, and the dye in the wastewater can almost be completely decolorized within 60 min under the conditions of pH = 2, the dosage of ribbons being 1.8 g/L and water bath temperature of 313 K, with the degradation efficiency and chemical oxygen demand removal being 96.05% and 51.73%, respectively. Furthermore, the Cu46Zr42Al7Y5 MG ribbon still shows superior structural stability and degradation performance after repeated use, and the corrosion pits on the MG surface promote the physicochemical reaction between the wastewater and the ribbons. [ABSTRACT FROM AUTHOR]

The oily wastewater was treated by electrocoagulation with Fe78Si9B13 amorphous ribbons as anode and graphite plates as cathode under such processing parameters as different pH values and current density, respectively. The degradation effect on the oily wastewater was characterized by chemical demand oxygen (COD), while the ribbons before and after using were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results indicate that under the conditions of pH = 3 and current density being 3.125 A/cm2, the optimal COD removal efficiency was obtained to be 73.22%. Compared with the ordinary crystalline iron plate, the COD removal efficiency of resultant wastewater degraded by the amorphous ribbons is more than doubled. Simultaneously, the Fe78Si9B13 amorphous ribbons exhibit good structural stability even after four cycles of using. [ABSTRACT FROM AUTHOR]

The effect of 1 at. % Cu addition and annealing temperatures on the soft magnetic properties of Fe81B13P3Si2C1 amorphous ribbons was investigated in this paper. The results show that both Fe81B13P3Si2C1 and (Fe81B13P3Si2C1)0.99Cu1 amorphous/nanocrystalline alloys possess excellent soft magnetic properties. Minor Cu addition can enlarge the temperature interval between first and second crystalline temperatures from 48 K to 112 K, enlarging the processing window and increasing the thermal stability of the amorphous alloy. The annealed Fe81B13P3Si2C1 amorphous/nanocrystalline alloy exhibits saturation flux densities (Bs) on the order of 1.69 T and coercivities (Hc) of 14.6 A/m, and the annealed (Fe81B13P3Si2C1)0.99Cu1 alloy shows a high Bs value of up to 1.92 T and Hc of 11.6 A/m. The soft magnetic properties were discussed in terms of microstructure and magnetic domain observation. [ABSTRACT FROM AUTHOR]

By using Zr41.2Ti13.8Ni10Cu12.5Be22.5 (Vit1) bulk metallic glass with a defined cooling history, the heat capacity (Cp) of liquid and glass, and the calorimetric glass transition in differential scanning calorimetry experiments were investigated. Then, a thermal equilibrium model related to the melting and solidifying process was established to extrapolate the solidification glass transition (SGT) temperature range during liquid to glassy solid phase transformation. By using the extrapolated SGT temperature range, the thermodynamic parameters, including the Cp and thermal conductivity (λ), were adjusted, which can make the simulated cooling temperature curves accurately reflect the recorded ones. The coincidence of experimental and simulation results indicates the rationality of the thermal equilibrium model established in the present work. Furthermore, it is proposed that the SGT is resulted from the falling out-of-equilibrium of the undercooled liquid metal that acts as an endothermic trap to suppress the occurrence of recalescence. [ABSTRACT FROM AUTHOR]

Compared with the conventional casting process, digital pattern-less casting technology has many advantages such as good machining accuracy, a short processing cycle, and low production cost. It is a new rapid manufacturing technology for castings, integrated with CAD/CAM, casting, CNC machining and many other advanced technologies. With this digital casting technology, no pattern is needed for making molds; it is precise, flexible, and green. Usually, art castings have complex structures and are made in small batches or even made in a single-piece, especially for large-sized art castings. So it has the shortcomings of high cost, low efficiency and long time for making a pattern to produce art castings with the conventional casting processes. However, the digital pattern-less casting technology can be applied to fabricate art castings, since it can greatly shorten the manufacturing cycle and lower the production cost, thus having a very good prospect. In this study, based on the digital pattern-less casting technology, a plaque casting with artistic Chinese characters (a Chinese poem) was designed and manufactured, and the production process was demonstrated in detail. [ABSTRACT FROM AUTHOR]

Sn60Pb40 alloy powders were fabricated using the planar flow casting (PFC) atomization process. By using OM, SEM and EPMA, the characteristics of the morphologies and microstructures of the powders have been investigated. It is observed that the environment of ambient gas in the atomization box has great effects on the morphology of the alloy powders. The microstructures of Sn60Pb40 alloy powders produced by the PFC atomization process are completely composed of eutectic, which is made up of both oversaturated α solid solution and β solid solution. The microstructures of small size powders are extraordinarily undeveloped dendritic eutectic, in which the large majority of the α phase appears nearly spherical, evidently since the cooling rate is higher and the under-cooling is larger. As for the large size powders, since the cooling rate and undercooling are relatively low, lamellar α phase apparently increases in the eutectic microstructures of these powders, and there is even typical lamellar eutectic structure clearly observed in some micro-areas. After remelting tests by DTA, the microstructures of small size powders are transformed, which become composed of large crumby α phase and eutectic (α+β), while those of large size powders change into classical tin-lead structures of primary α phase plus lamellar eutectic (α+β). By studying the microstructures of tin-lead alloy powders, a model has been proposed to predict the microstructure formation of Sn60Pb40 alloy powders. [ABSTRACT FROM AUTHOR]

The influences of minor amounts of scandium on the microstructure and mechanical properties of as-cast ZA27 alloy have been experimentally investigated. The experimental results show that as far as the Sc addition is individually concerned, the refinement result of the as-cast ZA27 alloy with 0.5wt.%Sc addition is comparatively better. After alloying with minor amounts of Sc, the coarse dendrites of the ZA27 alloy are refined and transformed into the uniform and small equiaxed grain microstructure; also the eutectics among the grain boundaries become finer. The test results of mechanical properties show that the tensile strength and hardness of the as-cast ZA27 alloy containing 0.5wt.%Sc approach 495 MPa and 120.2 HB, increase by 28.5% and 33.1%, respectively, compared with those of the ZA27 alloy with no addition of Sc element, while the elongation of the alloy is improved to 7.6% from 2.7%. The SEM, EDAX and XRD analyses show that in the ZA27 alloy, the trace element Sc combines with Al to form the square AI3Sc phase particles, which serve as heterogeneous nuclei, facilitating the refinement of the microstructure and the improvement of the mechanical properties of the alloy. [ABSTRACT FROM AUTHOR]