Spécifications techniques des NdFeB


  Neodymium Iron Boron (NdFeB) magnets, of the Rare Earth class, have been commercially available since the mid -1980's. Their popularity has grown rapidly due to their high Maximum Energy Product and their wide range of available shapes, sizes, and grades. 
  NdFeB magnets can be manufactured by sintering, compression bonding, injection molding, and extrusion. The sintered form holds the highest energy product of up to 48MGOe, while the bonded form holds a lower energy product of up to 10MGOe. The majority of NdFeB magnets are anisotropic and can only be magnetized in the orientation direction. In general, magnetizing fields of approximately 30KOe are required to saturate NdFeB magnets.
  These magnets are prone to corrosion in humid environments. For this, liquid epoxy, dry epoxy, nickel plating, zinc plating, and combinations of these coatings may be used as a protective measure. 
Surface Treatment Method:
   Zinc,Nickel,Tin,Phosphor,Silver or Gold Plating Spray Coating Epoxy Resin.
Typical Magnetic Performance For Sintered NdFeB Magnet 
Grade
Br
HcB
HcJ
(BH)max
Curie Temp.
Temp.Coe
working T.
US standard
[mT]
[Gs] 
[KA/m]
[Oe] 
[KA/m]
[Oe] 
[KJ/m3]
[MGOe]] 
[?]
[%/?]
[?]
MMPA
Equivalent 
N35
1180
11800 
860
10800
955
12000 
280
35 
310
0.12
80
RE35/12
N38
1230
12300 
875
11000 
955
12000 
300
38 
310
0.12
80
RE38/12
N40
1270
12700 
875
11000 
955
12000 
318
40 
310
0.12
80
RE40/12
N42
1300
13000 
875
11000 
955
12000 
334
42 
310
0.12
80
RE42/12
N45
1330
13300 
860
10800 
955
12000 
358
45 
310
0.12
80
RE45012
N35M
1180
11800 
860
10800 
1114
14000 
280
35 
320
0.12
100
RE35/14
N38M
1230
12300 
875
11000 
1114
14000 
300
38 
320
0.12
100
RE38/14
N40M
1270
12700 
875
11000 
1114
14000 
318
40 
320
0.12
100
RE40/14
N42M
1300
13000 
875
11000 
1114
14000 
334
42 
320
0.12
100
RE42/14
N45M
1330
13300 
860
10800 
1114
14000 
358
45 
320
0.12
100
RE45/14
N30H
1080
10800 
835
10500 
1353
17000 
240
30 
330
0.12
120
RE30/17
N33H
1140
11400 
835
10500 
1353
17000
365
33 
330
0.12
120
RE33/17
N35H
1180
11800 
860
10800 
1353
17000
280
35 
330
0.12
120
RE35/17
N38H
1230
12300 
875
11000 
1353
17000
300
38 
330
0.12
120
RE38/17
N40H
1270
12700 
875
11000 
1353
17000
318
40 
330
0.12
120
RE40/17
N42H
1300
13000 
860
10800 
1353
17000
334
42 
330
0.12
120
RE42/17
N30SH
1080
10800 
835
10500 
1592
20000 
240
30 
330
0.12
150
RE30/20
N33SH
1140
11400 
835
10500 
1592
20000
265
33 
330
0.12
150
RE33/20
N35SH
1180
11800 
860
10800 
1592
20000
280
35 
330
0.12
150
RE35/20
N38SH
1230
12300 
875
11000 
1592
20000
300
38 
330
0.12
150
RE38/20
N40SH
1270
12700 
875
11000 
1592
20000
318
40 
330
0.12
150
RE40/20
N28UH
1050
10500 
780
9800 
1989
25000 
223
28 
330
0.12
180
RE28/25
N30UH
1080
10800 
835
10500 
1989
25000 
240
30 
330
0.12
180
RE30/25
N33UH
1140
11400 
835
10500 
1989
25000 
265
33 
330
0.12
180
RE33/25
N25EH
1020
10200 
760
9600 
2387
30000 
200
25 
330
0.12
200
RE25/30
N28EH
1050
10500 
780
9800 
2387
30000
223
28 
330
0.12
200
RE28/30
N30EH
1080
10800 
835
10500 
2387
30000
240
30 
330
0.12
200
RE30/30


NdFeB Other Physical Properties
Temp.Coeff.of Br:
-0.11%/?

Density:
7.5g/cm[KJ/m3] 
Vickers Hardness:
600Hv
Tensile Strength:
8.0kg/m[KJ/m2]
Specific Heat:
0.12k Cal/(kg?)
oung's Modulus:
1.6×1011N/m[KJ/m2]
Poisson's Ratio:
0.24
Curie Temperature:
310-340?
Electrical Resistivity:
144
Flexural Strength:
25kg/mm[KJ/m2]
Coef.of Theral Expansion:
4×10-6/?
Therma conductivity:
7.7kcal/m.h.?
Rigidity:
0.64N/m[KJ/m2]/n
Compressibility:
9.8×1012m[KJ/m2]/N
Tmp.Coeff.of iHc:
-0.60%/?