Grain boundary and grain structure control through application of a high magnetic field

2006 ◽  
Vol 54 (6) ◽  
pp. 977-981 ◽  
Author(s):  
D.A. Molodov ◽  
P.J. Konijnenberg
Keyword(s):  
Magnetic Field ◽  
Grain Boundary ◽  
High Magnetic Field ◽  
Grain Structure ◽  
Structure Control

Structure Control of Hydroxyapatite Using a Magnetic Field

2007 ◽  
Vol 561-565 ◽  
pp. 1565-1568 ◽  
Author(s):  
Kazuhiko Iwai ◽  
Jun Akiyama ◽  
Shigeo Asai
Keyword(s):  
Magnetic Field ◽  
High Magnetic Field ◽  
Slip Casting ◽  
Casting Process ◽  
Ceramic Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Control ◽  
Crystal Alignment ◽  
The Magnetic Field

A high magnetic field is a useful tool to control the crystal alignment of ceramic materials. In this study, a horizontal 10T static magnetic field was imposed on slurry containing hydroxyapatite (HAp) crystals under the horizontal mold rotation during slip casting process so as to introduce uni-axial alignment for some amount of crystals in the sample, and then it was sintered in atmosphere without the magnetic field. From X-ray diffraction, it has been found that the HAp crystals in the sample treated with the mold rotation under the magnetic field were aligned its c-axis to a particular direction.

An Effect of High Magnetic Field on Grain Growth in Nanocrystalline Iron

2007 ◽  
Vol 539-543 ◽  
pp. 2793-2797 ◽  
Author(s):  
W.P. Tong ◽  
L.M. Wang ◽  
G.J. Ma ◽  
N.R. Tao ◽  
Liang Zuo
Keyword(s):  
Magnetic Field ◽  
Grain Growth ◽  
High Magnetic Field ◽  
Early Stage ◽  
Grain Structure ◽  
Surface Mechanical Attrition Treatment ◽  
Iron Sample ◽  
Mechanical Attrition ◽  
Different Temperatures ◽  
Nanocrystalline Iron

A nanostructured surface layer on a pure iron sample was prepared by surface mechanical attrition treatment (SMAT). The thermal stability of SMAT sample was investigated at different temperatures with or without a high magnetic field (H =12T). It was found that a high magnetically annealing enhanced grain growth at the early stage of annealing, and produced a uniform nanocrystalline grain structure. After homogeneous grains developed, further grain growth became restrained.

Grain boundary motion and grain growth in zinc in a high magnetic field

2013 ◽  
Vol 49 (11) ◽  
pp. 3875-3884 ◽  
Author(s):  
Dmitri A. Molodov ◽  
Christoph Günster ◽  
Günter Gottstein
Keyword(s):  
Magnetic Field ◽  
Grain Boundary ◽  
Grain Growth ◽  
High Magnetic Field ◽  
Boundary Motion ◽  
Grain Boundary Motion

scholarly journals Spinodal Decomposition in Fe-25Cr-12Co Alloys under the Influence of High Magnetic Field and the Effect of Grain Boundary

Nanomaterials ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 578 ◽  
Author(s):  
Lin Zhang ◽  
Zhaolong Xiang ◽  
Xiaodi Li ◽  
Engang Wang
Keyword(s):  
Magnetic Field ◽  
Heat Treatment ◽  
Grain Boundary ◽  
Spinodal Decomposition ◽  
High Magnetic Field ◽  
Shape Change ◽  
Atomic Mobility ◽  
Magnetic Performance ◽  
Simulation Results ◽  
Co Alloys

Fe-Cr-Co alloys precipitate nanosized α1 particles through spinodal decomposition, and their magnetic performance is susceptible to influence by the shape and arrangement of α1 particles. We studied spinodal decomposition during the heat treatment of Fe-Cr-Co alloys by both experimental and numerical simulation. Fe-Cr-Co alloys were fabricated first by directional solidification, followed by thermomagnetic treatment in a high magnetic field (HMF) and step aging. The experimental results show a spinodally decomposed structure consisting of nanosized α1 particles. The applied HMF caused the α1 phase to change into a rod-like shape. Moreover, a feather-like structure was observed near the grain boundary (GB), with slim α1 rods regularly arranged along the direction perpendicular to the GB. With the shape change and alignment of the α1 phase in the HMF, Fe-Cr-Co alloys show magnetic coercivity that is superior to those of samples without an HMF. To reveal the influence of HMF on phase transformations and the effect of GB, we conducted phase-field simulations of spinodal decomposition in the Fe-Cr-Co alloy. A migrating GB contributes to the elongation and arrangement of the α1 phase in the regions where the GB has passed. Thus, the α1 phase is arranged as parallel rods that are perpendicular to the GB. This GB effect consists of the effect of enhanced atomic mobility and the elastic energy. The α1 rods are elongated along the direction of HMF. The simulation results indicate that the feather-like structure is caused by a combined effect of both the GB and HMF. It is shown that the model generates microstructures which are qualitatively similar to those observed experimentally.

scholarly journals Diffusion in Copper/Cobalt Systems under High Magnetic Fields

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3104
Author(s):  
Zhiwei Zhang ◽  
Xiang Zhao ◽  
Sadahiro Tsurekawa
Keyword(s):  
Magnetic Field ◽  
Grain Boundary ◽  
Diffusion Couple ◽  
High Magnetic Field ◽  
Vacancy Concentration ◽  
Frequency Factor ◽  
Magnetic Field Direction ◽  
Enhanced Diffusion ◽  
Electron Probe Micro Analyzer ◽  
Diffusion Entropy

Comprehensive research on a high magnetic field’s effect on diffusion is lacking; hence, this study investigates the effect of the magnetization of such a field on diffusion using a copper/cobalt diffusion couple in the diamagnetic/ferromagnetic states, respectively. The diffusion couple was formed using explosive welding to avoid diffusion during manufacturing. The diffusion couple annealed within a temperature range of 1165 –1265 K under a 0–6-T high magnetic field. The angle between the diffusion and magnetic field directions was set as 0° and then 180°. The penetration profiles of cobalt volume diffusion in the copper and grain-boundary diffusion of copper in cobalt were constructed using an electron probe micro analyzer. The high magnetic field increased the volume diffusivity of cobalt in copper, but had no evident effect on the grain-boundary diffusivity of copper in cobalt, irrespective of the magnetic field direction. An Arrhenius plot of the cobalt volume diffusivity in copper demonstrated that the applied high magnetic field enhanced diffusion by changing the frequency factor rather than the activation energy; this can be attributed to the increased diffusion entropy caused by changing the vacancy concentration, which resulted from the introduction of magnetization under a high magnetic field.

Effect of longitudinal magnetic field on grain growth of hollow stud welded joint

2021 ◽  
Author(s):  
Wei Bai ◽  
DeKu Zhang ◽  
Hong yu Yin ◽  
KeHong Wang
Keyword(s):  
Magnetic Field ◽  
Grain Boundary ◽  
Grain Growth ◽  
Longitudinal Magnetic Field ◽  
Large Diameter ◽  
Large Angle ◽  
Grain Structure ◽  
Incomplete Fusion ◽  
Large Current ◽  
Stud Welding

Abstract Aiming at the defects of large diameter hollow stud welding such as arc blow and incomplete fusion,drawn arc stud welding with the longitudinal magnetic field was used to 30CrNi3MoV steel and Q235 stud. The grain growth process of joint was studied. With the assistance of longitudinal magnetic field, the arc action area on the end face of the hollow stud was increased, and the end face of stud was melted evenly. The solidification and crystallization process of molten pool was changed due to magnetic field stirring. Within a certain range, the microstructure of the joint is gradually refined and the size is homogeneous with the increase of magnetic field. But too large current can be attributed to the very coarse grain structure. Besides, the proportion of small angle grain boundary was decreased during appropriate magnetic field current, while the proportion of large angle grain boundary was increased. Meanwhile, preferred orientation of grains of the joints was changed due to the magnetic stirring.

Critical current of a highTcJosephson grain boundary junction in high magnetic field

1992 ◽  
Vol 61 (11) ◽  
pp. 1355-1357 ◽  
Author(s):  
M. Däumling ◽  
E. Sarnelli ◽  
P. Chaudhari ◽  
A. Gupta ◽  
J. Lacey
Keyword(s):  
Magnetic Field ◽  
Grain Boundary ◽  
Critical Current ◽  
High Magnetic Field
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