The effect of milling time on the microstructural evolution and magnetic properties of Ti50Fe50 alloys prepared by mechanical alloying were investigated. The results showed that the powder size was ...decreased sharply and then stabilized. Correspondingly, the milled powders experienced a transition from the lamellar shape to the spherical shape due to severe plastic deformation as well as the competition of cold welding and fracturing when the milling time was increased. Compared with the detailed composition primary powder (composed of Ti and α-Fe phases), the nanocrystalline Ti and α-Fe phase gradually disappeared and the amorphous phase were formed in the Ti50Fe50 alloys after milling for 40 h. When the milling time was increased to 60–90 h, the nanocrystalline disappeared and the complete amorphization of the milled Ti50Fe50 alloys occurred. However, a small amount of the nanocrystalline TiFe was formed except for a large of amorphous phase in Ti50Fe50 alloys for 100 h. Meanwhile, the formation of paramagnetic amorphous/nanocrystalline Ti and TiFe phase resulted in the saturation magnetization and coercive of the milled Ti50Fe50 alloys were decreased. Therefore, they exhibited excellent soft magnetic (0–90 h) and paramagnetic properties (100 h).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The effect of milling time on the microstructure evolution and soft magnetic properties of Ti50Fe50 alloy produced by mechanical alloying (MA) has been investigated. With the increase of milling ...time, the morphologies of Ti50Fe50 alloys experience a transition from lamellar structure to spherical structure, the α-Fe(Ti) solid solution containing a supersaturated Ti is formed, the grain sizes of Fe and Ti are decreased to nanoscale and their internal microstrains are increased. When the milling time is increased to 20h, the nanocrystalline TiFe intermetallic phase appears and the Ti-rich amorphous phase is formed along with the complete disappearance of crystal Ti phase. Additionally, the saturation magnetization (Ms) of the milled Ti50Fe50 alloys is reduced gradually, while the coercivity (Hc) exhibits an increasing trend. This is attributed to the combination reactions of nanocrystalline, microstrain, grain boundaries, paramagnetic Ti-rich amorphous, paramagnetic nanocrystalline TiFe and ferromagnetic α-Fe(Ti) phases. The magnetic hysteresis loops, the field cooled (FC) and zero field cooled (ZFC) curves confirm that the amorphous/nanocrystalline Ti50Fe50 alloys produced by MA can sever as excellent soft magnetic materials.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•Amorphous/crystalline coatings were prepared by laser cladding with rectangular spot.•Laser remelting can decrease cracks, and improve the surface quality of cladding coating.•Laser ...remelting can refine the microstructure and induce the formation of amorphous phases.•Laser remelting can enhance the corrosion resistant and microhardness of cladding coating.
The WC reinforced Fe-based amorphous composite coatings were prepared by laser cladding with rectangular spot. The effect of laser remelting on the microstructure and properties of composite coatings was investigated. The results showed that laser remelting can reduce the cracks and porosities of the cladding coating and improve its surface quality. Large amounts of crystalline phases were precipitated at the top of the cladding and remelting coatings. However, the microstructure at the top of the remelting coating was finer compared to that at the top of the cladding coating. With increasing distance from the surface of substrate, the amorphous phase appeared within the remelting coating and large amounts of carbides rich in Fe and Mo, Fe23B6, γ-Fe and Cr9.1Si0.9 phases were also precipitated in the remelting coating. As a result, the corrosion resistance of the remelting coating was higher than that of the cladding coating. The microhardness of the remelting coating was approximately 1.13 times higher than that of the cladding coating.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The Ti-Fe-based alloys were in-situ synthesized by the combination of mechanical alloying and laser melting deposition (LMD). The microstructure evolution and corrosion behaviors of Ti50Fe50 and ...Ti40Fe50Cu10 alloys were also investigated. The results show that mechanical alloying of Ti and Fe elemental mixtures induces the formation of intermetallic TiFe, Ti-rich amorphous phase and α-Fe(Ti) solid solution and that the addition of Cu can refine the size of nanocrystalline TiFe phase. Although LMD-produced Ti50Fe50 and Ti40Fe50Cu10 alloys are composed of TiO dendrites and α-Fe/TiFe2 (hexagonal MgZn2-type Laves structure) eutectic, the addition of Cu can refine the TiO dendrites, induce the formation of TiO2 particles and dissolve into the TiFe2 phase in the Ti40Fe50Cu10 alloy. As a result, the LMD-produced Ti40Fe50Cu10 alloy exhibits higher corrosion resistance than the LMD-produced Ti50Fe50 alloy.
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•TiO/Ti-Fe alloys are synthesized by mechanical alloying and laser melting deposition.•Mechanical alloying of Ti and Fe powders results in nanocrystalline TiFe and α-Fe(Ti).•Addition of Cu can refine the size of nanocrystalline TiFe phase.•LMD-produced Ti50Fe50 and Ti40Fe50Cu10 alloys consist of TiO and α-Fe/TiFe2 eutectic.•Addition of Cu can refine the microstructure and enhance the corrosion resistance.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The electromagnetic shielding materials with characteristics of ultrathin, lightweight and high strength are the most advantageous materials in electromagnetic shielding. In this work, novel carbon ...fiber nonwoven composites with interlayer microstructure were designed and prepared. Due to their special structure, carbon fiber nonwoven composites coated with polyaniline by means of electropolymerization showed excellent electromagnetic shielding (65 dB) and mechanical properties (bending strength of 457 MPa). More intriguing, the absolute SE (Shielding Effectiveness) of the composites can be as high as 3904 dB.cm
2
/g. In order to explore the elementary mechanisms of electromagnetic loss, the relevant calculation of electromagnetic shielding effectiveness was carried out. The experimental and theoretical results show that the reflection is the dominant shielding performance of the carbon fiber nonwoven composites. However, with the increase of electropolymerization time, the absorption loss was enhanced and the reflection was weakened, which was caused by the conductive polyaniline network structure covered on the nonwoven fiber surface. Based on the comparison between experimental results and theoretical calculation, the effect of multiple reflection loss on the total electromagnetic shielding performance was improved, and the loss mechanism of multiple reflection was analyzed in detail. Moreover, the surface roughness of fiber and the formation of polymerization products by electropolymerization could effectively enhance the interfacial strength between carbon fiber nonwoven and epoxy, which observably increased the bending strength by 83%.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
All-fiber acousto-optical modulation of polarisation maintaining fiber is of great importance in fiber optics. Previous researchers generally studied one-channel all-fiber acousto-optical modulator ...of polarisation maintaining fiber. In order to develop the great capability of optical fiber, the multiple-channel all-fiber acousto-optical modulator of polarisation maintaining fiber should be concerned. This paper discusses multiple-channel all-fiber acousto-optical modulator of polarisation maintaining fiber theoretically. The perturbed coupled-mode theory is used to discuss the solutions of coupled-mode equations for optical fiber when there are multiple parts being perturbed, and the multiple-channel modulation is analyzed. The theoretical result coincides with the experimental research very well.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
A study was conducted to evaluate the effect of yeast peptide supplementation on growth performance, nutrient digestibility, and blood metabolites in geese. One-day-old Sichuan white geese (n = 300, ...95.16 ± 1.98 g) were randomly assigned to five dietary treatment groups containing either 0 (control), 100, 200, 300, or 400 mg/kg commercial yeast peptide product. Compared with the control, dietary supplemental yeast peptide at 200 mg/kg substantially improved feed conversion ratio, body slope length, half-eviscerated percentage, and the apparent digestibility of phosphorus. With the increase in dietary yeast peptide, breast width, carcass percentage, serum triglyceride and high-density lipoprotein increased linearly. The average daily gain, pelvis width, half-diving depth, low density lipoprotein, and digestibility of gross energy exhibited quadratic responses with the increase in dietary yeast peptide, with the 200 mg/kg or 300 mg/kg feeding level being the most effective. It can be concluded that dietary supplementation of yeast peptides improves growth performance and affects nutrient digestibility and blood metabolites, which were optimized at 200 mg/kg or 300 mg/kg of yeast peptide in the present study.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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