RARE EARTH MAGNET

Item Unit Nd-Fe-B Sm-Co
Compositon Nd2•Fe14•B Sm2Co17
Molding Process Imposing magnetic field
on the magnet
Imposing magnetic field
on the magnet
Residual Flux Density
Br
mT 1210 to 1270 970 to 1020
kG 12.1 to 12.7 9.7 to 1.02
Coercive Force
bHc
kA/m 867 to 979 557 to 836
KOe 10.9 to 12.3 7 to10.5
Intrinsic Coercive Force
iHc
kA/m >1353 716 to 1194
KOe >17 9 to 15
Maximum Energy Product
(BH) max
kJ/m2 278 to 310 175 to 199
MGOe 35 to 39 22 to 25
Temperature Coefficent Br %/ K -0.12 -0.04
Temperature Coefficent iHc %/ K -0.58 -0.03
Curie Point
Tc
K 593 1093
°C 320 820
Recoil Relative Magnetic
Permeability
μrec
1.05 1.05
Density g/cm2 7.4 8.3
Deflecting Strength Mpa 245 118
Kgf/mm2 25 12
Compression Strength MPa 1050 500 to 519
2 107 51 to 53
Tensile Strength MPa 44 36
Kgf/mm2 4.5 3.6
Specific Heat J/(Kg•K) 0.50x103 034x103
cal/g°C 0.12 0.08
Vickers Hardness HV 600 550
Thermal Expansion Coefficient
Vertical
ppm/K 5.5 to 7.5 8
Thermal Expansion Coefficient
Vertical
ppm/K -3 to 0.5 11
JIS REFe280/120 RECo160/70
MMPA
Magnetic Field To Be Charged
For Magnetization
kA/m 2400 1990
KOe 30 25
Electric Resistance nΩm 1.3x10-4 0.8 to 0.9