Controllable fabrication of silica encapsulated soft magnetic microspheres with enhanced oxidation-resistance and their rheology under magnetic field

2012 ◽  
Vol 403 ◽  
pp. 133-138 ◽  
Author(s):  
Ying Dan Liu ◽  
Hyoung Jin Choi ◽  
Seung-Bok Choi
Keyword(s):  
Magnetic Field ◽  
Oxidation Resistance ◽  
Magnetic Microspheres ◽  
Soft Magnetic ◽  
Enhanced Oxidation ◽  
Controllable Fabrication

scholarly journals Preparation of MCrAlY–Al2O3 Composite Coatings with Enhanced Oxidation Resistance through a Novel Powder Manufacturing Process

2019 ◽  
Vol 28 (3) ◽  
pp. 433-443 ◽  
Author(s):  
Mingwen Bai ◽  
Bo Song ◽  
Liam Reddy ◽  
Tanvir Hussain
Keyword(s):  
Oxidation Resistance ◽  
Manufacturing Process ◽  
Composite Powder ◽  
Composite Coatings ◽  
Submicron Particles ◽  
Second Phase ◽  
Mcraly Coatings ◽  
Powder Feedstock ◽  
Enhanced Oxidation ◽  
Powder Manufacturing

Abstract MCrAlY–Al2O3 composite coatings were prepared by high-velocity oxygen fuel thermal spraying with bespoke composite powder feedstock for high-temperature applications. Powder processing via a suspension route was employed to achieve a fine dispersion of α-Al2O3 submicron particles on the MCrAlY powder surface. This was, however, compromised by ~ 50% less flowability of the feedstock during spraying. Nevertheless, the novel powder manufacturing process introduced in this study has shown potential as an alternative route to prepare tailored composite powder feedstock for the production of metal matrix composites. In addition, the newly developed MCrAlY–Al2O3 composite coatings exhibited superior oxidation resistance, compared to conventional MCrAlY coatings, with the formation of nearly exclusively Al2O3 scale after isothermal oxidation at 900 °C for 10 h. The addition of α-Al2O3 particles in the MCrAlY coatings as a second phase was found to have promoted the formation of YAG oxides (YxAlyOz) during spraying and also accelerated the outwards diffusion of Al, which resulted in enhanced oxidation resistance.

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.

Novel synthesis of 1,5-disubstituted-1,2,3-triazolines catalysed by Zepto magnetic microspheres under the influence of a rotating magnetic field

2019 ◽  
Vol 97 (3) ◽  
pp. 163-168 ◽  
Author(s):  
Priyanka Sharma ◽  
Srinivasu V. Vallabhapurapu ◽  
Wei H. Ho ◽  
Nanjundaswamy M. Hemmaragala
Keyword(s):  
Magnetic Field ◽  
Magnetic Force ◽  
Rotating Magnetic Field ◽  
Magnetic Microspheres ◽  
The Novel ◽  
Aryl Azides ◽  
Alkyl Aryl ◽  
Novel Synthesis ◽  
Bead Diameter ◽  
Magnetic Poles

The novel reactor has been designed to perform chemical reactions under the influence of a magnetic field generated by alternating magnetic poles as a function of time. The system was successfully employed to synthesize a series of 1,5-disubstituted-1,2,3-triazolines via the regioselective [3 + 2] cycloaddition reactions between alkyl/aryl azides and nitroolefins catalysed by Zepto (para magnetic ultra-blue carboxy functionalized) microspheres (bead diameter 2.5 μm). All of the reactions went smoothly without any adverse effect on nitro, cyano, thienyl, hydroxy, halogens, and ether functions at 25 ± 2 °C and afforded 82%–99% pure products at a magnetic field of 18.99 mT and an exposure time of 180–240 min. The influence of the magnetic force exerted on the magnetic materials was found to enhance the catalytic activity of microspheres. The catalyst could easily be separated by simple centrifugation, which could be reused for at least 15 runs with no loss in activity.

Soft Magnetic Films and Wires for Magnetic Field Sensors

2008 ◽  
pp. 1708-1741
Author(s):  
A. S. Antonov ◽  
I. T. Iakubov ◽  
A. N. Lagarkov ◽  
A. L. Rakhmanov ◽  
I. A. Ryjikov
Keyword(s):  
Magnetic Field ◽  
Magnetic Films ◽  
Soft Magnetic ◽  
Magnetic Field Sensors ◽  
Soft Magnetic Films

Magnetic Field Enhancement with Soft Magnetic Flux Guides

2008 ◽  
Vol 587-588 ◽  
pp. 313-317
Author(s):  
D.C. Leitão ◽  
I.G. Trindade ◽  
R. Fermento ◽  
João P. Araújo ◽  
S. Cardoso ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Spin Valve ◽  
Field Enhancement ◽  
High Permeability ◽  
Soft Magnetic ◽  
Field Amplification ◽  
Close Proximity ◽  
Magnetic Field Enhancement ◽  
The Magnetic Field

In this work, a study of the sensitivity enhancement of spin valve sensors, when located in close proximity to magnetic flux guides, is presented. The magnetoresistance (MR) of spin-valve sensors, lithographically patterned into stripes with lateral dimensions, (length) l = 500 µm, (width) wsensor = 1, 2, 6 µm and placed near one/two Co93.5Zr2.8Nb3.7 (CZN) magnetic flux guide, is characterized at room temperature. CZN has a high permeability that together with a defined microstructured shape, is able to concentrate the magnetic flux in a small area, leading to an increase in sensor's sensitivity. The magnetic field amplification is estimated by comparison of sensor sensitivity with/without magnetic flux guides, in the linear operation range, and studied as a function of different parameters. Besides an enhancement in sensitivity, sensors also exhibit an important increase in the hard axis coercivity and a shift from MR(H=0) = 0.5, both attributed to the magnetic flux guides. Amplification factors of the order of 20 are observed..

scholarly journals Enhanced oxidation resistance of active nanostructures via dynamic size effect

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Yun Liu ◽  
Fan Yang ◽  
Yi Zhang ◽  
Jianping Xiao ◽  
Liang Yu ◽  
...  
Keyword(s):  
Size Effect ◽  
Oxidation Resistance ◽  
Enhanced Oxidation
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