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

A general grain size determination technique for Al-Si casting alloys

1999 ◽  
Vol 11 (4) ◽  
pp. 211-218 ◽  
Author(s):  
A. Tronche ◽  
D. Gloria ◽  
J. E. Gruzleski
Keyword(s):  
Grain Size ◽  
Size Determination ◽  
Casting Alloys

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.

Studies on Nd(Fe/sub 0.92-x/B/sub 0.08/Ga/sub x/)/sub 5.5/ sintered permanent magnets

1990 ◽  
Author(s):  
R. Grossinger ◽  
X.C. Kou ◽  
R. Krewenka ◽  
H.R. Kirchmayr ◽  
M. Tokunaga
Keyword(s):  
Permanent Magnets ◽  
Sintered Permanent Magnets
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