On the role of the grain size in the magnetic behavior of sintered permanent magnets

2018 ◽  
Vol 531 ◽  
pp. 159-163
Author(s):  
K.G. Efthimiadis ◽  
N. Ntallis
Keyword(s):  
Grain Size ◽  
Permanent Magnets ◽  
Magnetic Behavior ◽  
Sintered Permanent Magnets

Nucleus Size Determination for Nd2Fe14B, Sm2Co17, SmCo5 and BaFe12O19 Magnets

2012 ◽  
Vol 727-728 ◽  
pp. 151-156 ◽  
Author(s):  
Marcos Flavio de Campos ◽  
José Adilson de Castro
Keyword(s):  
Grain Size ◽  
Legendre Polynomials ◽  
Permanent Magnets ◽  
Critical Size ◽  
Size Determination ◽  
Nucleus Size ◽  
Spherical Cap ◽  
Global Energy ◽  
Domain Configuration ◽  
Sintered Permanent Magnets

The nucleus size was determined for the following phases: Nd2Fe14B, Sm2Co17, SmCo5and BaFe12O19. These phases are the basis for the most relevant sintered permanent magnets. For the determination, it was assumed a spherical grain, and that the reversal of magnetization occurs in a tiny shell near the surface. The Magnetostatic energy for each domain configuration was found by means of Legendre polynomials. The nucleus is a spherical cap, near the equator. After reaching the nucleus critical size, the reversal of magnetization continues spontaneously, reducing the global energy of the system. It was found that, for each grain size, there is a different nucleus size.

The dependence of coercivity and corrosion resistance on grain size in Nd-Fe-B-type sintered permanent magnets

1991 ◽  
Vol 3 (31) ◽  
pp. 5893-5901 ◽  
Author(s):  
S Szymura ◽  
H Bala ◽  
Yu M Rabinovich ◽  
V V Sergeev ◽  
G Pawlowska ◽  
...  
Keyword(s):  
Grain Size ◽  
Corrosion Resistance ◽  
Permanent Magnets ◽  
Sintered Permanent Magnets

MICROSTRUCTURE AND COERCIVITY IN (Nd, Dy)-(Fe, Co)-B BASED SINTERED PERMANENT MAGNETS WITH MINOR Nb AND Ga ADDITIONS

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-573-C8-574
Author(s):  
G. F. Zhou ◽  
X. K. Sun ◽  
Y. C. Chuang ◽  
L. Gao ◽  
Z. Yu ◽  
...  
Keyword(s):  
Permanent Magnets ◽  
Sintered Permanent Magnets

Magnetic Properties of xCeO2•(50 − x) PbO•50B2O3 Glasses and Glass Ceramics

2017 ◽  
Vol 13 (1) ◽  
pp. 4486-4494 ◽  
Author(s):  
G.El Damrawi ◽  
F. Gharghar
Keyword(s):  
Magnetic Properties ◽  
Large Scale ◽  
Glass Ceramics ◽  
Magnetic Behavior ◽  
Crystal Formation ◽  
Dual Roles ◽  
Effective Agent ◽  
Ordered Structures ◽  
Essential Change

Cerium oxide in borate glasses of composition xCeO2·(50 − x)PbO·50B2O3 plays an important role in changing both microstructure and magnetic behaviors of the system. The structural role of CeO2 as an effective agent for cluster and crystal formation in borate network is clearly evidenced by XRD technique. Both structure and size of well-formed cerium separated clusters have an effective influence on the structural properties. The cluster aggregations are documented to be found in different range ordered structures, intermediate and long range orders are the most structures in which cerium phases are involved. The nano-sized crystallized cerium species in lead borate phase are evidenced to have magnetic behavior.  The criteria of building new specific borate phase enriched with cerium as ferrimagnetism has been found to keep the magnetization in large scale even at extremely high temperature. Treating the glass thermally or exposing it to an effective dose of ionized radiation is evidenced to have an essential change in magnetic properties. Thermal heat treatment for some of investigated materials is observed to play dual roles in the glass matrix. It can not only enhance alignment processes of the magnetic moment but also increases the capacity of the crystallite species in the magnetic phases. On the other hand, reverse processes are remarked under the effect of irradiation. The magnetization was found to be lowered, since several types of the trap centers which are regarded as defective states can be produced by effect of ionized radiation. 

scholarly journals On the role of grain size on slurry erosion behavior of a novel medium-carbon, low-alloy pipeline steel after induction hardening

Wear ◽  
2021 ◽  
pp. 203678
Author(s):  
Vahid Javaheri ◽  
Oskari Haiko ◽  
Saeed Sadeghpour ◽  
Kati Valtonen ◽  
Jukka Kömi ◽  
...  
Keyword(s):  
Grain Size ◽  
Pipeline Steel ◽  
Induction Hardening ◽  
Slurry Erosion ◽  
Medium Carbon ◽  
Erosion Behavior

Spin-Lattice Coupling and Peculiarities of Magnetic Behavior of Ferrimagnetic Ludwigites Mn0.52+M1.52+Mn3+BO5(M=Cu, Ni)

2015 ◽  
Vol 233-234 ◽  
pp. 133-136 ◽  
Author(s):  
Leonard Bezmaternykh ◽  
Evgeniya Moshkina ◽  
Evgeniy Eremin ◽  
Maxim Molokeev ◽  
Nikita Volkov ◽  
...  
Keyword(s):  
Temperature Field ◽  
Low Temperature ◽  
Magnetic Anisotropy ◽  
Single Crystals ◽  
Magnetic Behavior ◽  
Temperature Hysteresis ◽  
Spin Lattice ◽  
Field Magnetization ◽  
Lattice Coupling

Temperature-field and orientational magnetization dependences of single crystals were measured. Both samples demonstrate significant field-depending temperature hysteresis and low-temperature counter field magnetization. The correlation of orientational dependences of these effects and magnetic anisotropy is analyzed; the role of spin-lattice interactions is discussed.

Structure of Low Cobalt Alloy for Permanent Magnets of Basis System Fe-Cr-Co at Complex Two-Level Loading in Isothermal Conditions

2007 ◽  
Vol 539-543 ◽  
pp. 2928-2933 ◽  
Author(s):  
V.S. Yusupov ◽  
A.I. Milyaev ◽  
Galia F. Korznikova ◽  
Alexander V. Korznikov ◽  
J.K. Kovneristii
Keyword(s):  
Grain Size ◽  
Active Zone ◽  
Single Phase ◽  
Permanent Magnets ◽  
Phase Region ◽  
The Body ◽  
Coarse Grained ◽  
Isothermal Conditions ◽  
Basis System ◽  
Level Loading

Results of experimental research into evolution of the structure and microhardness of the hard magnetic Fe-30Cr-8Co-0,7Ti-0,5V-0,7Si alloy during complex two-level loading (compression + torsion) in isothermal conditions at various temperatures in single-phase region are reported. It was revealed that the deformation leads to a strong refinement of initial coarse-grained structure in the whole volume of the sample, however the generated structure is non-uniform through the body of the sample. In an active zone of deformation, near to mobile head, there is a microcrystalline layer with a grain size of about 5 microns which thickness poorly depends on the formation. With removal from the active zone of deformation the grain size increases, and microhardness decreases.

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