Effect of Rapid Quenching in Magnetic Field on the Microstructures and Electrochemical Performances of AB5-Type Alloys

2012 ◽  
Vol 512-515 ◽  
pp. 1589-1596
Author(s):  
You Gen Tang ◽  
Chen Xi Jiang ◽  
Ya Zhi Wang ◽  
Xiao Pei Gao ◽  
Jin Bao Zhang
Keyword(s):  
Magnetic Field ◽  
Grain Size ◽  
Melt Spinning ◽  
Rapid Quenching ◽  
Electrochemical Performances ◽  
Electrochemical Studies ◽  
Cycle Stability ◽  
Oriented Growth ◽  
Cell Parameters ◽  
Diffusion Of Hydrogen

Direct magnetic field was imposed during the process of rapid quenching by melt spinning of MlNi3.6Co0.7Mn0.4Al0.3 and MlNi3.6Co0.35Mn0.5Al0.3Cu0.25. The effect of rapid quenching in magnetic field on the microstructures and electrochemical performances was investigated in detail. The results show that rapid quenching decreases the grain size of both alloys, and magnetic field results in an oriented growth especially for MlNi3.6Co0.35Mn0.5Al0.3Cu0.25 alloys, but they have little influence on the typical CaCu5 structure of AB5-type alloys except for the increase of cell parameters (a0, c0) and cell volume. Electrochemical studies indicate that rapid quenching enhances the cycle stability significantly but inevitably decreases the electrochemical capacities of the alloys unless magnetic field was imposed. Additionally, the diffusion of hydrogen and rate properties are improved with the emergence of magnetic field compared with the alloys processed by rapid quenching only.

scholarly journals The Effect of External Magnetic Field on Microstructure and Magnetic Properties of Melt-Spun Nd-Fe-B/Fe-Co Nanocomposite Ribbons

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Xuan Truong Nguyen ◽  
Hong Ky Vu ◽  
Hung Manh Do ◽  
Van Khanh Nguyen ◽  
Van Vuong Nguyen
Keyword(s):  
Magnetic Field ◽  
Grain Size ◽  
High Performance ◽  
Melt Spinning ◽  
Nominal Composition ◽  
Energy Product ◽  
Melt Spun ◽  
Spinning Process ◽  
Reduction Effect ◽  
Microstructure And Magnetic Properties

The ribbons Nd2Fe14B/Fe-Co were prepared with the nominal composition Nd16Fe76B8/40% wt. Fe65Co35by the conventional and the developed magnetic field-assisted melt-spinning (MFMS) techniques. Both ribbons are nanocomposites with the smooth single-phase-like magnetization loops. The 0.32 T magnetic field perpendicular to the wheel surface and assisting the melt-spinning process reduces the grain size inside the ribbon, increases the texture of the ribbon, improves the exchange coupling, and, in sequence, increases the energy product(BH)maxof the isotropic powdered samples of MFMS ribbon in ~9% by comparison with that of the ribbon melt-spun conventionally. The grain size reduction effect caused by the assisted magnetic field has also been described quantitatively. The MFMS technique seems to be promising for producing high-performance nanocomposite ribbons.

scholarly journals Influence Of Cooling Rate On Phase Composition And Magnetic Properties Of Sm12.5Co66.5Fe8Cu11Si2 Alloy In The Form Of Ribbon In As-Quenched State

2015 ◽  
Vol 60 (2) ◽  
pp. 667-670
Author(s):  
M. Dośpiał ◽  
M. Nabiałek ◽  
K. Błoch
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Melt Spinning ◽  
Magnetic Measurements ◽  
Rapid Quenching ◽  
Vibrating Sample Magnetometer ◽  
Fabrication Method ◽  
Entire Volume ◽  
Diffraction Patterns ◽  
Hard Magnetic Properties

Abstract The fabrication method and magnetic properties of Sm12.5Co66.5Fe8Cu11Si2 alloy are presented in this article. The samples were produced by rapid quenching of the liquid alloy onto a rotating, copper wheel (the so-called ‘melt-spinning’ method) and they had a thin ribbon shape. The microstructure of the samples was investigated by measurements of diffraction patterns for powdered samples, in order to obtain data from the entire volume of the sample. It was found, that samples were composed of different amounts of Sm2Co17, SmCo5 and SmCo7 phases, depending on the linear velocity of the copper wheel used during the fabrication process. The magnetic measurements were performed using a vibrating sample magnetometer (LakeShore VSM) working with an external magnetic field of up to 2 T. It was found that the obtained ribbons displayed relatively good hard magnetic properties, such as remanence μ0MR, and high resistance to demagnetization fields JHC.

scholarly journals On the through-process texture evolution assessment in grain oriented Fe-3 wt% Si steel produced by a novel directional inoculation technique

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Snehashish Tripathy ◽  
Sandip Ghosh Chowdhury
Keyword(s):  
Magnetic Field ◽  
Hot Rolling ◽  
Texture Evolution ◽  
Lattice Parameter ◽  
Soft Magnetic ◽  
Oriented Growth ◽  
Inoculation Technique ◽  
Hot Band ◽  
Ebsd Technique ◽  
Cast Microstructure

AbstractA novel directional inoculation technique has been designed to cast thin slab ingots containing Goss (or near Goss) oriented components in the as cast microstructure under the combined effect of oriented nucleation and oriented growth. The same has been targeted so as to retain Goss orientations and simultaneously develop γ fiber components (ranging from {111}<$$1\overline{1}0$$ 1 1 ¯ 0 > to {111}<112>) during hot rolling. The designed scheme of directional inoculation achieved oriented nucleation by the effect of exogenously added soft magnetic inoculants under magnetic field and oriented growth by the effect of fast cooling rates prevailing in the mould. The choice of 65Fe–35Co (wt%) system as soft magnetic inoculants was made taking into account the similarity in crystal structure and lattice parameter. The chemically synthesized inoculants under the effect of external magnetic field during solidification were able to exhibit directional inoculation. Variation in the cast microstructure and microtexture by varying the extent of inoculant addition was studied by EBSD technique. The ingots cast under different conditions were subjected to a designed hot rolling schedule and the through process microstructural and microtextural evolution was assessed. It was observed that fine equiaxed grains with initial cube orientations in the as cast structure could lead to the most desirable microstructural as well as microtextural gradient in the hot band.

Activated Nitrogen-Enriched Carbon/Reduced Expanded Graphite Composites for Supercapacitors

2011 ◽  
Vol 211-212 ◽  
pp. 440-444 ◽  
Author(s):  
Shu Hui Tong ◽  
Chuan Li Qin ◽  
Zheng Jin ◽  
Xue Song Wang ◽  
Xu Duo Bai
Keyword(s):  
Electrode Material ◽  
In Situ Polymerization ◽  
Expanded Graphite ◽  
Mechanical Mixture ◽  
Electrochemical Measurements ◽  
Electrochemical Performances ◽  
Cycle Stability ◽  
Symmetric Supercapacitor ◽  
Graphite Composites

Activated nitrogen-enriched carbon/reduced expanded graphite composites (ANC/REG-c) with different composite ratio were prepared by in-situ polymerization, carbonization, activation and reduction of aniline and expanded graphite. These were characterized by XPS, SEM and electrochemical measurements. XPS shows that N atoms exist in the ANC and ANC/REG-c. Compared to mechanical mixture of ANC and REG(ANC/REG-m), ANC/REG-c shows lower resistance and higherCp1(185.4 F/g) vs 124.3 F/g of ANC/REG-m measured by CV due to the introduction of the composite sturcture. When the composite ratio of ANC/REG-c is 6:1, the ANC/REG-c shows the highestCp1(264.0 F/g) and its symmetric supercapacitor also shows the best synthetical electrochemical performances. The optimal supercapacitor presents good cycle stability. ANC/REG-c is a suitable electrode material for supercapacitors.

Structure, Magnetic Properties and Hyperfine Parameters of Nd-Substituted Ni-Fe-Ga Heusler Alloys

MRS Advances ◽  
2017 ◽  
Vol 2 (25) ◽  
pp. 1341-1346
Author(s):  
Monica Sorescu ◽  
Felicia Tolea ◽  
Mihaela Valeanu ◽  
Mihaela Sofronie
Keyword(s):  
Melt Spinning ◽  
Magnetic Measurements ◽  
Heusler Alloys ◽  
Hyperfine Magnetic Field ◽  
Rapid Quenching ◽  
Linear Least Squares ◽  
X Ray Diffraction ◽  
Hyperfine Parameters ◽  
X Ray ◽  
Field Distributions

ABSTRACTSamples of Ni57-xNdxFe18Ga25 with x=2 and 4 were prepared in ribbon form by rapid quenching via melt spinning route. The samples were analyzed by X-ray diffraction (XRD), magnetic measurements and Mössbauer spectroscopy, both in the as-quenched form and after thermal annealing at 900 oC for 2 min and 400 °C for 2 hours. For x=2 the Nd atoms are completely dissolved in the Ni-Fe-Ga matrix, while for x=4 the additional occurrence of the secondary 2:17 phase could be resolved. These findings were supported by the analysis of hyperfine magnetic field distributions obtained from the non-linear least-squares fitting of the Mössbauer spectra.

Enhanced Electrochemical Hydrogen Storage Characteristics of the as-Spun Mg2Ni-Type Alloys by Substituting Ni with M (M=Cu, Co)

2012 ◽  
Vol 457-458 ◽  
pp. 572-577
Author(s):  
Yang Huan Zhang ◽  
Bao Wei Li ◽  
Hui Ping Ren ◽  
Zai Guang Pang ◽  
Zhong Hui Hou ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Melt Spinning ◽  
Nanocrystalline Structure ◽  
Amorphous Structure ◽  
High Rate ◽  
Electrochemical Performances ◽  
Secondary Phases ◽  
Nanocrystalline And Amorphous ◽  
Electrochemical Hydrogen Storage ◽  
Rate Discharge

Mg2Ni-type Mg20Ni10-xMx (M=Cu, Co; x=0, 1, 2, 3, 4) electrode alloys with nanocrystalline and amorphous structure were synthesized by melt-spinning technique. The microstructures of the as-spun alloys were characterized by XRD, SEM and HRTEM. The electrochemical hydrogen storage properties of the experimental alloys were measured. The obtained results show that the as-spun (M=Cu) alloys hold an entire nanocrystalline structure, whereas the as-spun (M=Co) alloys display a nanocrystalline and amorphous structure, confirming that the substitution of Co for Ni facilitates the glass formation in the Mg2Ni-type alloy. Furthermore, such substitution results in the formation of secondary phases Mg2Cu and MgCo2 instead of changing the major phase of Mg2Ni. The substitution of M (M=Cu, Co) for Ni markedly improves the electrochemical performances of the alloys, involving the discharge capacity and the cycle stability as well as the high rate discharge ability.

Macro and Microstructural Effects of the Application of an Induced Axial Magnetic Field During the Deposition of Aluminum Weld Beads

2009 ◽  
Vol 1242 ◽  
Author(s):  
M. A. García ◽  
V. H. López M. ◽  
R. García H. ◽  
F. F. Curiel L. ◽  
R. R. Ambríz R.
Keyword(s):  
Magnetic Field ◽  
Grain Size ◽  
Magnetic Fields ◽  
Weld Metal ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Axial Magnetic Field ◽  
Grain Structure ◽  
Bead Geometry ◽  
External Power Source

ABSTRACTIn this work, aluminum weld beads were deposited on aluminum plates of commercial purity (12.7 mm thick), using an ER-5356 filler wire. The aim of the experiments was to assess the effects that yield the induction of an axial magnetic field (AMF) during the application of the weld beads using the direct current gas metal arc welding process (DC-GMAW). An external power source was use to induce magnetic fields between 0 to 28 mT. The effects of the magnetic fields were assessed in terms of the macrostructural features of the deposits, morphology of the grain structure, grain size and grain size distribution in the weld metal. Macrostructural characteristics of the weld beads revealed that increasing the intensity of the magnetic induction to produce a magnetic field above 14 mT, leads to a significant loss of feeding material and there is a tendency of the deposits to increase their width and reduce penetration. Perturbation of the weld pool induced by the application of the AMF noticeably modified the grain structure in the weld metal. In particular, for the intensities of 5 and 14 mT, columnar growth was essentially non-existent. Grain size distribution plots showed, generally speaking, that the use of magnetic fields is an efficient method to produce homogeneous grain structures within the weld metal. Finite element analysis was used to explain the weld bead geometry with the intensity of the magnetic field.

scholarly journals Synthesis and electrochemical performances of Na3V2(PO4)2F3/C composites as cathode materials for sodium ion batteries

RSC Advances ◽  
2019 ◽  
Vol 9 (53) ◽  
pp. 30628-30636 ◽  
Author(s):  
Mingxue Wang ◽  
Xiaobing Huang ◽  
Haiyan Wang ◽  
Tao Zhou ◽  
Huasheng Xie ◽  
...  
Keyword(s):  
Solid State ◽  
Carbon Source ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
Sodium Ion ◽  
Electrochemical Performances ◽  
Sodium Ion Batteries ◽  
Rate Performance ◽  
Cycle Stability ◽  
Reaction Method

Na3V2(PO4)2F3/C composites were synthesized by a solid-state reaction method using pitch as the carbon source, the as-prepared sample with the carbon content of 12.14% possesses an excellent rate performance and cycle stability.

Giant Magnetoimpedance in as Quenched Fe Based Nanocrystalline Ribbons

2005 ◽  
Vol 475-479 ◽  
pp. 2219-2222 ◽  
Author(s):  
Ji Fan Hu ◽  
Hong Wei Qin ◽  
Minhua Jiang ◽  
Bo Li ◽  
Dongliang Zhao ◽  
...  
Keyword(s):  
Grain Size ◽  
Magnetic Materials ◽  
Melt Spinning ◽  
Experimental Results ◽  
Soft Magnetic Materials ◽  
Soft Magnetic ◽  
Giant Magnetoimpedance ◽  
Giant Magnetoimpedance Effect ◽  
Additional Annealing ◽  
Melt Spinning Technique

FeCuNbSiB and FeZrBCu nanocrystalline ribbons can be obtained directly through the melt- spinning technique without additional annealing processes. The giant magnetoimpedance can be observed in FeCuNbSiB and FeZrBCu as quenched ribbons. The addition of Cu improves the nano-crystallization of a-Fe(Si) or a-Fe phase and reduces the grain size in FeCuNbSiB and FeZrBCu as quenched ribbons, which enhances the magnetoimpedance via increasing the variation of permeability under fields. The present experimental results reveal a novel route to fabricate the Fe based nanocrystalline soft magnetic materials with giant magnetoimpedance effect.

Microstructures and electrochemical performances of La2Mg(Ni0.85Co0.15)9Crx (x=0–0.2) electrode alloys prepared by casting and rapid quenching

2005 ◽  
Vol 144 (1) ◽  
pp. 255-261 ◽  
Author(s):  
Yang-Huan Zhang ◽  
Xiao-Ping Dong ◽  
Guo-Qing Wang ◽  
Shi-Hai Guo ◽  
Xin-Lin Wang
Keyword(s):  
Rapid Quenching ◽  
Electrochemical Performances
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