The Experts below are selected from a list of 5346 Experts worldwide ranked by ideXlab platform
Akihisa Inoue - One of the best experts on this subject based on the ideXlab platform.
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high frequency soft magnetic properties of fe si b p mo cu amorphous and Nanocrystalline Alloys
Journal of Non-crystalline Solids, 2019Co-Authors: E N Zanaeva, Akihisa Inoue, A I Bazlov, D A Milkova, Yu A Churyumov, Yu N Tabachkova, Fengwu Wang, F L Kong, Shengli ZhuAbstract:Abstract This paper deals with formation, thermal stability and magnetic properties of Fe-Si-B-P-Mo amorphous and Nanocrystalline Alloys with minor Cu alloying. Amorphous melt-spun Fe84-85B8P3.5-4Mo1-2Cu0.5-1 (at%) alloy ribbons show good bending plasticity and crystallize through two stages with each onset temperature of about 673 and 813 K. Good soft magnetic properties were obtained in both amorphous and Nanocrystalline (bcc-Fe + amorphous) states. The highest saturation magnetization and the lowest coercivity are ∼1.4 T and ∼4 A/m, respectively, for the amorphous phase and 1.8 T and 2.5 A/m, respectively, for the bcc-Fe + amorphous phases. The frequency dependence of permeability for Nanocrystalline Fe84B8P3.5Si1.5Mo2Cu1 alloy remains nearly constant in a wide frequency range up to 65 kHz. Besides, the quality factor is higher over the whole frequency range up to 10 MHz for the Nanocrystalline than for the amorphous alloy. These characteristics are promising for future engineering of high-frequency type soft magnetic materials.
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soft magnetic properties and microstructure of fe84 xnb2b14cux Nanocrystalline Alloys
Materials & Design, 2014Co-Authors: Akihisa Inoue, Weiming Yang, Chuntao Chang, Xinmin Wang, Runwei Li, Baolong ShenAbstract:Magnetic properties and microstructure of new Fe84-xNb2B14Cux Nanocrystalline Alloys were investigated. We found that the microstructure was refined and soft magnetic properties of this alloy system were enhanced with proper Cu addition and annealing conditions. It was also discovered that the mean grain size firstly increases, then decreases to a minimum, and finally increases again with increasing annealing temperature for Fe83Nb2B14Cu1 Nanocrystalline alloy, and this phenomenon was interpreted by the grain growth mechanism. Moreover, after annealing at 813 K for 180 s, Fe83Nb2B14Cu1 Nanocrystalline alloy shows a fine microstructure with mean grain size of 16 nm, and exhibits excellent soft magnetic properties, such as high saturation magnetic flux density (1.7 T), low coercivity (7 A/m) and high permeability (2.8 x 10(4)). The result indicates that this alloy should have a promising application in the soft magnetic industry. (C) 2013 Elsevier Ltd. All rights reserved.
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Soft magnetic properties and microstructure of Fe84−xNb2B14Cux Nanocrystalline Alloys
Materials & Design (1980-2015), 2014Co-Authors: Lin Xue, Akihisa Inoue, Weiming Yang, Haishun Liu, Lintao Dou, Chuntao Chang, Xinmin Wang, Baolong ShenAbstract:Magnetic properties and microstructure of new Fe84-xNb2B14Cux Nanocrystalline Alloys were investigated. We found that the microstructure was refined and soft magnetic properties of this alloy system were enhanced with proper Cu addition and annealing conditions. It was also discovered that the mean grain size firstly increases, then decreases to a minimum, and finally increases again with increasing annealing temperature for Fe83Nb2B14Cu1 Nanocrystalline alloy, and this phenomenon was interpreted by the grain growth mechanism. Moreover, after annealing at 813 K for 180 s, Fe83Nb2B14Cu1 Nanocrystalline alloy shows a fine microstructure with mean grain size of 16 nm, and exhibits excellent soft magnetic properties, such as high saturation magnetic flux density (1.7 T), low coercivity (7 A/m) and high permeability (2.8 x 10(4)). The result indicates that this alloy should have a promising application in the soft magnetic industry. (C) 2013 Elsevier Ltd. All rights reserved.
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low core loss of fe85si2b8p4cu1 Nanocrystalline Alloys with high bs and b800
Journal of Alloys and Compounds, 2011Co-Authors: Takeshi Kubota, Akihiro Makino, Akihisa InoueAbstract:Abstract The Fe–Si–B–P–Cu Nanocrystalline Alloys exhibit high saturation magnetic flux density (Bs) as well as good soft magnetic properties such as low coercivity, high effective permeability and low magnetostriction after nanocrystallization. In this paper, the Fe85Si2B8P4Cu1 alloy has been newly developed. On the viewpoint of magnetic softness, the Fe85Si2B8P4Cu1 Nanocrystalline alloy reveals low core loss (W) at a commercially frequency of 50 Hz in the maximum induction (Bm) range of up to 1.75 T, and the W in the Bm range of less than 1.8 T is smaller than that of the highest-graded oriented Si-steel due to high magnetic flux density at 800 A/m (B800) of above 1.8 T and excellent magnetic softness originated from much higher Fe content and uniform Nanocrystalline structure with small magnetostriction. The electrical resistivity (ρ) is relative higher than Si-steels. Thus the Fe–Si–B–P–Cu Alloys are attractive for applying to magnetic parts such as motors, transducers, choke-coils and so-forth.
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new fe metalloids based Nanocrystalline Alloys with high bs of 1 9t and excellent magnetic softness
Journal of Applied Physics, 2009Co-Authors: Akihiro Makino, Takeshi Kubota, Kunio Yubuta, Akihisa InoueAbstract:The melt-spun Fe83.3–84.3Si4B8P3–4Cu0.7 Alloys have a heterogeneous amorphous structure including a large amount of α‐Fe-like clusters. Compared with the FeSiB Alloys, the particle size rapidly decreases from several hundred nanometers to 2–3nm due to the proper amounts of simultaneous P and Cu additions. By controlling the crystallization process, a homogeneous Nanocrystalline structure composed by small α‐Fe grains with size of 10–17nm in diameter can be realized from the heterogeneous amorphous Alloys. The nanocrystallized Fe83.3–84.3Si4B8P3–4Cu0.7 Alloys show the extremely high saturation magnetic flux density of 1.88–1.94T sufficiently near to 1.97T of Fe‐3.5mass%Si crystalline soft magnetic Alloys, and exhibit low coercivity of less than 10A∕m and higher effective permeability of 16 000–25 000 at 1kHz due to the simultaneous realization of the homogeneous Nanocrystalline structure and the small magnetostriction of (2–3)×10−6. In addition, the Nanocrystalline Alloys exhibit the superior core loss to ...
Baolong Shen - One of the best experts on this subject based on the ideXlab platform.
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High Bs of FePBCCu Nanocrystalline Alloys with excellent soft-magnetic properties
Journal of Non-Crystalline Solids, 2020Co-Authors: Long Hou, Weiming Yang, Haishun Liu, Xingdu Fan, Qiang Luo, Baolong ShenAbstract:Abstract High saturation magnetic flux density (Bs) Nanocrystalline Alloys are increasingly attractive due to their unique microstructure and outstanding magnetic performance. In this work, we report that the substitution of B for P essentially improves the Bs of FePBCCu amorphous Alloys. Based on high Bs amorphous matrix, the Fe83.2P8B2C6Cu0.8 Nanocrystalline alloy with high Bs of 1.77 T, low coercivity of 3.6 A/m and high effective permeability of 20,600 was developed. Such magnetic performance of Fe83.2P8B2C6Cu0.8 Nanocrystalline alloy is closely associated with the uniform refined composite microstructure, where the α-Fe nanocrystals with high volume fraction, small size and high number density (~1.8 × 1023 m − 3) were formed. This finding makes the FePBCCu composite a kind of promising soft-magnetic material in electrical and electronic fields.
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Effect of Co addition on the magnetic properties and microstructure of FeNbBCu Nanocrystalline Alloys
Journal of Magnetism and Magnetic Materials, 2016Co-Authors: Lin Xue, Anding Wang, Weiming Yang, Haishun Liu, Chuntao Chang, He Men, Baolong ShenAbstract:Abstract Through gradient substitution of Co for Fe, the magnetic properties and microstructures of (Fe 1− x Co x ) 83 Nb 2 B 14 Cu 1 ( x =0.1, 0.2, 0.3, 0.4, 0.5) Nanocrystalline Alloys were investigated. Because of the strong ferromagnetic exchange coupling between Co and Fe, substantial improvement in saturation magnetization was achieved with proper levels of Co addition. Meanwhile, the Curie temperature increased noticeably with increasing Co addition. After heat treatment, the (Fe 0.9 Co 0.1 ) 83 Nb 2 B 14 Cu 1 Nanocrystalline alloy showed a refined microstructure with an average grain size of 10–20 nm, exhibiting a comparatively high saturation magnetization of 1.82 T and a lower coercivity of 12 A/m compared to other Hitperm-type Alloys with higher Co contents. Additionally, the Curie temperature reached 1150 K upon introduction of Co. As the soft magnetic properties are strengthened by adding a small amount of Co, the combination of fine, soft magnetic properties and low cost make this Nanocrystalline alloy a potential magnetic material.
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soft magnetic properties and microstructure of fe84 xnb2b14cux Nanocrystalline Alloys
Materials & Design, 2014Co-Authors: Akihisa Inoue, Weiming Yang, Chuntao Chang, Xinmin Wang, Runwei Li, Baolong ShenAbstract:Magnetic properties and microstructure of new Fe84-xNb2B14Cux Nanocrystalline Alloys were investigated. We found that the microstructure was refined and soft magnetic properties of this alloy system were enhanced with proper Cu addition and annealing conditions. It was also discovered that the mean grain size firstly increases, then decreases to a minimum, and finally increases again with increasing annealing temperature for Fe83Nb2B14Cu1 Nanocrystalline alloy, and this phenomenon was interpreted by the grain growth mechanism. Moreover, after annealing at 813 K for 180 s, Fe83Nb2B14Cu1 Nanocrystalline alloy shows a fine microstructure with mean grain size of 16 nm, and exhibits excellent soft magnetic properties, such as high saturation magnetic flux density (1.7 T), low coercivity (7 A/m) and high permeability (2.8 x 10(4)). The result indicates that this alloy should have a promising application in the soft magnetic industry. (C) 2013 Elsevier Ltd. All rights reserved.
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Soft magnetic properties and microstructure of Fe84−xNb2B14Cux Nanocrystalline Alloys
Materials & Design (1980-2015), 2014Co-Authors: Lin Xue, Akihisa Inoue, Weiming Yang, Haishun Liu, Lintao Dou, Chuntao Chang, Xinmin Wang, Baolong ShenAbstract:Magnetic properties and microstructure of new Fe84-xNb2B14Cux Nanocrystalline Alloys were investigated. We found that the microstructure was refined and soft magnetic properties of this alloy system were enhanced with proper Cu addition and annealing conditions. It was also discovered that the mean grain size firstly increases, then decreases to a minimum, and finally increases again with increasing annealing temperature for Fe83Nb2B14Cu1 Nanocrystalline alloy, and this phenomenon was interpreted by the grain growth mechanism. Moreover, after annealing at 813 K for 180 s, Fe83Nb2B14Cu1 Nanocrystalline alloy shows a fine microstructure with mean grain size of 16 nm, and exhibits excellent soft magnetic properties, such as high saturation magnetic flux density (1.7 T), low coercivity (7 A/m) and high permeability (2.8 x 10(4)). The result indicates that this alloy should have a promising application in the soft magnetic industry. (C) 2013 Elsevier Ltd. All rights reserved.
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FePCCu Nanocrystalline Alloys with excellent soft magnetic properties
Science China Technological Sciences, 2012Co-Authors: Yunlong Jin, Xincai Liu, Xingdu Fan, He Men, Baolong ShenAbstract:The effect of Cu addition on crystallization behavior and soft magnetic properties of Fe84−xP10C6Cux (x = 0−1.15) Alloys was investigated. Low-cost FePCCu Nanocrystalline Alloys dispersed with α-Fe phase with an average grain size of 15–35 nm were obtained by appropriately annealing the melt-spun ribbons at 683 K for 5 min. The Fe83.25P10C6Cu0.75 Nanocrystalline alloy exhibits a high Bs of 1.65 T, low Hc of 3.3 A/m and high µe at 1 kHz of 21 100, which is superior to the traditional FePC soft magnetic Alloys. The core loss is as low as 0.32 W/kg at 1.0 T and 50 Hz, which is 60% that of nonoriented Fe 6.5 mass% Si-steel. It is encouraging to synthesize this Fe-based Nanocrystalline alloy with excellent soft-magnetic properties even using commercially industry-grade raw materials, which is promising for the future industrial applications.
Christopher A. Schuh - One of the best experts on this subject based on the ideXlab platform.
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Phase transitions in stable Nanocrystalline Alloys
Journal of Materials Research, 2017Co-Authors: Arvind R. Kalidindi, Christopher A. SchuhAbstract:Grain boundary segregation can reduce the driving force for grain growth in Nanocrystalline materials and help retain fine grain sizes. However, grain boundary segregation is enthalpically driven, and so a stabilized Nanocrystalline state should undergo a disordering process as temperature is increased. Here we develop a Monte Carlo-based simulation that determines the minimum free energy state of an alloy with a strong tendency for grain boundary segregation that considers both different grain sizes and a large solute configuration space. We find that a stable Nanocrystalline alloy undergoes a disordering process where grain boundary segregated atoms dissolve into the adjacent grains and increase the grain size as a function of temperature. At a critical temperature, the single crystal state becomes the most preferred. Using this method, we are able to determine how the grain size changes as a function of temperature and produce equilibrium phase diagrams for Nanocrystalline Alloys.
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duplex Nanocrystalline Alloys entropic nanostructure stabilization and a case study on w cr
Journal of Materials Research, 2015Co-Authors: Tongjai Chookajorn, Mansoo Park, Christopher A. SchuhAbstract:Grain boundary (GB) segregation can markedly improve the stability of nanostructured Alloys, where the fraction of GB sites is inherently large. Here, we explore the concept of entropically supported GB segregation in Alloys with a tendency to phase-separate and its role in stabilizing nanostructures therein. These duplex Nanocrystalline Alloys are notably different, both in a structural and thermodynamic sense, from the previously studied “classical” Nanocrystalline Alloys, which are solid solutions with GB segregation of solute. Experiments are conducted on the W–Cr system, in which nanoduplex structures are expected. Upon heating ball-milled W–15 at.% Cr up to 950 °C, a nanoscale Cr-rich phase was found along the GBs. These precipitates mostly dissolved into the W-rich grains leaving behind Cr-enriched GBs upon further heating to 1400 °C. The presence of Cr-rich nanoprecipitates and GB segregation of Cr is in line with prediction from our Monte Carlo simulation when GB states are incorporated into the alloy thermodynamics.
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Enhanced solid solution effects on the strength of Nanocrystalline Alloys
Acta Materialia, 2011Co-Authors: Timothy J. Rupert, Jonathan C. Trenkle, Christopher A. SchuhAbstract:Abstract Solid solution strengthening in Nanocrystalline Alloys is studied using sputtered Ni–W as a model system. In the composition range of 0–20 at.% W, the sputtered Alloys have a Nanocrystalline structure with a grain size that is independent of composition. Nanoindentation of these Alloys shows that solute addition increases strength to very high levels, almost in proportion to the solute content. This behavior is not expected based on traditional solid solution strengthening mechanistic models of local dislocation pinning at solute atoms, but can be explained by further considering a global effect of solute on the average properties of the Ni lattice. The new strengthening term arises by considering grain boundaries as pinning points for dislocation motion in Nanocrystalline materials and incorporating the effect of solutes on such a mechanism. Our discussion surrounding Ni–W also provides insights into other solid solution Nanocrystalline systems, a variety of which we show can be accurately described using the same concept. These developments also explain the origin of solid solution softening in some Nanocrystalline Alloys.
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microstructural evolution during the heat treatment of Nanocrystalline Alloys
Journal of Materials Research, 2007Co-Authors: Andrew J Detor, Christopher A. SchuhAbstract:Nanocrystalline Alloys often show exceptional thermal stability as a consequence of kinetic and thermodynamic impediments to grain growth. However, evaluating the various contributions to stability requires detailed investigation of the solute distribution, which is challenging within the fine structural-length-scales of Nanocrystalline materials. In the present work, we use a variety of techniques to assess changes in the grain size, chemical ordering, grain-boundary segregation, and grain-boundary structure during the heat treatment of Ni–W specimens synthesized over a wide range of grain sizes from 3 to 70 nm. A schematic microstructural evolution map is also developed based on analytical models of the various processes activated during annealing, highlighting the effects of alloying in Nanocrystalline materials.
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tailoring and patterning the grain size of Nanocrystalline Alloys
Acta Materialia, 2007Co-Authors: Andrew J Detor, Christopher A. SchuhAbstract:Abstract Nanocrystalline Alloys that exhibit grain boundary segregation can access thermodynamically stable or metastable states with the average grain size dictated by the alloying addition. Here we consider Nanocrystalline Ni–W Alloys and demonstrate that the W content controls the grain size over a very broad range: ∼2–140 nm as compared with ∼2–20 nm in previous work on strongly segregating systems. This trend is attributed to a relatively weak tendency for W segregation to the grain boundaries. Based upon this observation, we introduce a new synthesis technique allowing for precise composition control during the electrodeposition of Ni–W Alloys, which, in turn, leads to precise control of the Nanocrystalline grain size. This technique offers new possibilities for understanding the structure–property relationships of Nanocrystalline solids, such as the breakdown of Hall–Petch strength scaling, and also opens the door to a new class of customizable materials incorporating patterned nanostructures.
Xinmin Wang - One of the best experts on this subject based on the ideXlab platform.
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compositional design and crystallization mechanism of high bs Nanocrystalline Alloys
Materials Research Bulletin, 2019Co-Authors: Tao Liu, Anding Wang, Xinmin Wang, Chengliang Zhao, Shiqiang Yue, C.t. LiuAbstract:Abstract High Bs Nanocrystalline Alloys (HBNAs) are increasingly attractive due to their unique microstructure and outstanding magnetic properties. It is important to clearly explore the crystallization mechanism to provide reliable and efficient composition design methods. In this study, composition design rules are proposed under the considerations of high amorphous forming ability (AFA) and microstructure refinement. These rules were verified in designing a FeSiBPCCu alloy system with excellent magnetic performance. The crystallization mechanism was investigated by exploring the microstructure evaluation process and the effects of Cu on the nucleation and crystallization processes. The addition of Cu stimulates the crystallization process, leading to the formation of a uniform microstructure with fine grains. The microstructure evaluation process was also clearly exhibited, which could explain the changes in the magnetic properties during the annealing process. The results are of great significance and shed light on the crystallization mechanism of HBNAs.
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high performance fe based Nanocrystalline Alloys with excellent thermal stability
Journal of Alloys and Compounds, 2019Co-Authors: Anding Wang, Tao Liu, Lei Xie, Xinmin Wang, C.t. Liu, J H Luan, Yong YangAbstract:Abstract Fe-based Alloys are an important soft magnetic material that plays a pivotal role in a variety of energy-related industrial applications, such as electric transformers, motors and converters. However, the trade-off between magnetic softness and saturation magnetization (Bs) has been hindering the development of next-generation Fe-based soft magnetic materials. In this work, we demonstrate a facile route to obtain nanostructured Fe-based alloy out of a marginal glass former, which exhibits a core-shell like nanostructure and a synergetic increase of Bs, magnetic permeability (μe) and hardness upon thermal annealing, giving rise to a unique combination of Bs > 1.83 T, μe ∼25000 and ultrahigh hardness of ∼15 GPa. In terms of the combined magnetic/mechanical properties, the nanostructured Fe-based alloy outperforms the variety of Fe-based soft magnetic Alloys hitherto reported. Furthermore, compared to the existing high performance soft magnetic Fe-based Nanocrystalline Alloys, the core-shell like nanostructure in our Fe-based Nanocrystalline alloy displays an excellent thermal stability, which offers a large time window which would facilitate materials processing for future large-scale industrial production.
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surface crystallization and magnetic properties of fecusibnbmo melt spun Nanocrystalline Alloys
Materials Research Bulletin, 2017Co-Authors: Fangpei Wan, Anding Wang, Chuntao Chang, Tao Liu, Fengyu Kong, Muqin Tian, Jiancheng Song, Jianhua Zhang, Xinmin WangAbstract:Abstract Fe 82 Cu 1 Si 4 B 11.5 Nb 1.5 −x Mo x ( x = 0, 0.75 and 1.5 at. %) Nanocrystalline Alloys were prepared using a melt-spinning technique and the effects of Mo content on thermal stability, soft magnetic properties and microstructure evolution were investigated. It was found that the Mo addition can improve the amorphous-forming ability and inhibit surface crystallization in a low vacuum atmosphere which may be due to better oxidative resistance. All the Alloys exhibited excellent soft-magnetic properties with low coercivity of 8.9–10.8 A/m, high effective permeability of 11,500–11,900 at 1 kHz and high saturation magnetic flux density of 1.67–1.72 T after annealing at optimal annealing conditions. In addition, the Alloys containing Mo have better transient effective permeability stability with increase in frequency. Decreasing the melt-spinning wheel speed can widen the annealing temperature range for Fe 82 Cu 1 Si 4 B 11.5 Nb 1.5 ribbon. Results indicate that these soft-magnetic Nanocrystalline materials have good manufacturability for industrial production.
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Improvement of magnetic properties for V-substituted Fe73.5Si13.5B9Cu1Nb3−xVx Nanocrystalline Alloys
Journal of Materials Science: Materials in Electronics, 2017Co-Authors: Han Yabin, Anding Wang, Chuntao Chang, Ran Wei, Li Zichao, Xinmin WangAbstract:The effects of V element on microstructural evolution and soft magnetic properties of Fe73.5Si13.5B9Cu1Nb3−xVx (x = 0, 0.5,1, 1.5 and 2, at.%) Nanocrystalline Alloys annealed at one-step and two-step state were investigated. As a result of an adequate addition of V, the microstructure and soft magnetic properties of the Nanocrystalline Alloys have greatly changed. The Alloys with higher V content are prone to form large grain size nanocomposite structure with better thermal stability but slightly worsen soft magnetic properties. However, the strategy of two-step annealing technique effectively refines grain and thereby improves the soft magnetic properties of the Alloys. The Nanocrystalline alloy with V = 1.5 after two-step annealing exhibits combined excellent soft magnetic properties, including a lower coercivity (H c= 0.89 A/m), enhanced saturation magnetization (B s over 1.3 T), high effective permeability? µ e = 26,400 at 1 kHz) and low core loss. The work shows that adopting a preheating procedure before the primary nanocrystallization stage, viz. to use two-step annealing technique instead of the routinely used one-step nanocrystallization stage,is an effective solution to the disadvantage of the decrease of Nb.
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Fe(Co)SiBPCCu Nanocrystalline Alloys with high B s above 1.83 T
Journal of Magnetism and Magnetic Materials, 2017Co-Authors: Tao Liu, Anding Wang, Chuntao Chang, Fengyu Kong, Lei Xie, Xinmin Wang, C.t. LiuAbstract:Abstract Fe84.75-xCoxSi2B9P3C0.5Cu0.75 (x = 0, 2.5 and 10) Nanocrystalline Alloys with excellent magnetic properties were successfully developed. The fully amorphous alloy ribbons exhibit wide temperature interval of 145–156 °C between the two crystallization events. It is found that the excessive substitution of Co for Fe greatly deteriorates the magnetic properties due to the non-uniform microstructure with coarse grains. The Alloys with x = 0 and 2.5 exhibit high saturation magnetization (above 1.83 T), low core loss and relatively low coercivity (below 5.4 A/m) after annealing. In addition, the Fe84.75Si2B9P3C0.5Cu0.75 Nanocrystalline alloy also exhibits good frequency properties and temperature stability. The excellent magnetic properties were explained by the uniform microstructure with small grain size and the wide magnetic domains of the alloy. Low raw material cost, good manufacturability and excellent magnetic properties will make these Nanocrystalline Alloys prospective candidates for transformer and motor cores.
Chuntao Chang - One of the best experts on this subject based on the ideXlab platform.
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surface crystallization and magnetic properties of fecusibnbmo melt spun Nanocrystalline Alloys
Materials Research Bulletin, 2017Co-Authors: Fangpei Wan, Anding Wang, Chuntao Chang, Tao Liu, Fengyu Kong, Muqin Tian, Jiancheng Song, Jianhua Zhang, Xinmin WangAbstract:Abstract Fe 82 Cu 1 Si 4 B 11.5 Nb 1.5 −x Mo x ( x = 0, 0.75 and 1.5 at. %) Nanocrystalline Alloys were prepared using a melt-spinning technique and the effects of Mo content on thermal stability, soft magnetic properties and microstructure evolution were investigated. It was found that the Mo addition can improve the amorphous-forming ability and inhibit surface crystallization in a low vacuum atmosphere which may be due to better oxidative resistance. All the Alloys exhibited excellent soft-magnetic properties with low coercivity of 8.9–10.8 A/m, high effective permeability of 11,500–11,900 at 1 kHz and high saturation magnetic flux density of 1.67–1.72 T after annealing at optimal annealing conditions. In addition, the Alloys containing Mo have better transient effective permeability stability with increase in frequency. Decreasing the melt-spinning wheel speed can widen the annealing temperature range for Fe 82 Cu 1 Si 4 B 11.5 Nb 1.5 ribbon. Results indicate that these soft-magnetic Nanocrystalline materials have good manufacturability for industrial production.
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soft magnetic fe si b cu Nanocrystalline Alloys with high cu concentrations
Journal of Alloys and Compounds, 2017Co-Authors: Xingjie Jia, Chuntao Chang, Guoqiang Xie, Wei ZhangAbstract:Abstract High saturation magnetic flux density (Bs) soft magnetic Nanocrystalline Alloys with good manufacturability were developed in a simple Fe-Si-B-Cu alloy system with high Cu concentrations. The Nanocrystalline Alloys with high Bs of ∼1.77 T and low coercivity of ∼7.1 A/m were obtained by annealing the melt-spun Fe-Si-B-Cu Alloys containing 1.7–2.0 at% Cu. The high content of Cu facilitates the formation of high-number-density α-Fe nuclei with an average grain size of ∼6 nm pre-existing in the amorphous matrix, which inhibits the excessive growth of the α-Fe grains by their competitive growth even during the low-heating-rate annealing, resulting in a fine nanostructure and excellent soft magnetic properties.
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Improvement of magnetic properties for V-substituted Fe73.5Si13.5B9Cu1Nb3−xVx Nanocrystalline Alloys
Journal of Materials Science: Materials in Electronics, 2017Co-Authors: Han Yabin, Anding Wang, Chuntao Chang, Ran Wei, Li Zichao, Xinmin WangAbstract:The effects of V element on microstructural evolution and soft magnetic properties of Fe73.5Si13.5B9Cu1Nb3−xVx (x = 0, 0.5,1, 1.5 and 2, at.%) Nanocrystalline Alloys annealed at one-step and two-step state were investigated. As a result of an adequate addition of V, the microstructure and soft magnetic properties of the Nanocrystalline Alloys have greatly changed. The Alloys with higher V content are prone to form large grain size nanocomposite structure with better thermal stability but slightly worsen soft magnetic properties. However, the strategy of two-step annealing technique effectively refines grain and thereby improves the soft magnetic properties of the Alloys. The Nanocrystalline alloy with V = 1.5 after two-step annealing exhibits combined excellent soft magnetic properties, including a lower coercivity (H c= 0.89 A/m), enhanced saturation magnetization (B s over 1.3 T), high effective permeability? µ e = 26,400 at 1 kHz) and low core loss. The work shows that adopting a preheating procedure before the primary nanocrystallization stage, viz. to use two-step annealing technique instead of the routinely used one-step nanocrystallization stage,is an effective solution to the disadvantage of the decrease of Nb.
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Fe(Co)SiBPCCu Nanocrystalline Alloys with high B s above 1.83 T
Journal of Magnetism and Magnetic Materials, 2017Co-Authors: Tao Liu, Anding Wang, Chuntao Chang, Fengyu Kong, Lei Xie, Xinmin Wang, C.t. LiuAbstract:Abstract Fe84.75-xCoxSi2B9P3C0.5Cu0.75 (x = 0, 2.5 and 10) Nanocrystalline Alloys with excellent magnetic properties were successfully developed. The fully amorphous alloy ribbons exhibit wide temperature interval of 145–156 °C between the two crystallization events. It is found that the excessive substitution of Co for Fe greatly deteriorates the magnetic properties due to the non-uniform microstructure with coarse grains. The Alloys with x = 0 and 2.5 exhibit high saturation magnetization (above 1.83 T), low core loss and relatively low coercivity (below 5.4 A/m) after annealing. In addition, the Fe84.75Si2B9P3C0.5Cu0.75 Nanocrystalline alloy also exhibits good frequency properties and temperature stability. The excellent magnetic properties were explained by the uniform microstructure with small grain size and the wide magnetic domains of the alloy. Low raw material cost, good manufacturability and excellent magnetic properties will make these Nanocrystalline Alloys prospective candidates for transformer and motor cores.
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Effect of Co addition on the magnetic properties and microstructure of FeNbBCu Nanocrystalline Alloys
Journal of Magnetism and Magnetic Materials, 2016Co-Authors: Lin Xue, Anding Wang, Weiming Yang, Haishun Liu, Chuntao Chang, He Men, Baolong ShenAbstract:Abstract Through gradient substitution of Co for Fe, the magnetic properties and microstructures of (Fe 1− x Co x ) 83 Nb 2 B 14 Cu 1 ( x =0.1, 0.2, 0.3, 0.4, 0.5) Nanocrystalline Alloys were investigated. Because of the strong ferromagnetic exchange coupling between Co and Fe, substantial improvement in saturation magnetization was achieved with proper levels of Co addition. Meanwhile, the Curie temperature increased noticeably with increasing Co addition. After heat treatment, the (Fe 0.9 Co 0.1 ) 83 Nb 2 B 14 Cu 1 Nanocrystalline alloy showed a refined microstructure with an average grain size of 10–20 nm, exhibiting a comparatively high saturation magnetization of 1.82 T and a lower coercivity of 12 A/m compared to other Hitperm-type Alloys with higher Co contents. Additionally, the Curie temperature reached 1150 K upon introduction of Co. As the soft magnetic properties are strengthened by adding a small amount of Co, the combination of fine, soft magnetic properties and low cost make this Nanocrystalline alloy a potential magnetic material.
