Neodymium Iron Boron Magnets

Dexter uses only licensed neodymium and licensed magnet materials for all applications.

Sintered neodymium-iron-boron (Nd-Fe-B) magnets are licensed rare earth magnets which are the most powerful commercialized permanent magnets available today, with maximum energy product ranging from 26 MGOe to 52 MGOe. Neodymium Iron Boron is the third generation of permanent magnet developed in the 1980s. It has a combination of very high remanence and coercivity and comes with a wide range of grades, sizes and shapes. With its excellent magnetic characteristics Nd-Fe-B offers  flexibility for new designs or as a replacement for traditional magnet materials such as ceramic, Alnico and Sm-Co for achieving higher efficiency and more compact devices.

A powder metallurgy process is used in producing sintered Neodymium magnets. Although sintered Neodymium is mechanically stronger than Samarium Cobalt magnets and less brittle than other magnets, it should not be used as a structural component. Selection of Nd-Fe-B is limited by temperature due to its irreversible loss and moderately high reversible temperature coefficient of Br and Hci. The maximum application temperature is 200 °C for high coercivity grades. Nd-Fe-B magnets are more prone to oxidation than any other magnet alloys. If Nd-Fe-B magnet is to be exposed to humidity, chemically aggressive media such as acids, alkaline solutions salts and harmful gases, coating is recommended. It is not recommended in a hydrogen atmosphere.

grade(click to view demagnetization curve)
max energy product
residual induction
min intrinsic coercivity
Coercivity
Max Operating Temp
Curie Temp
Coefficient Induction
20-150°C
Coefficient Coercivity
20-150°C
 
BHmax
Br
Hci
Hc
Tmax
Tc
α
β
 
MGOe
kG
kOe
kOe
°C
°C
% / °C
% / °C
52
14.5
11
10.6
50
310
-0.12
-0.65
50
14.3
11
10.6
50
310
-0.12
-0.63
48
13.9
11
10.6
50
310
-0.12
-0.63
45
13.6
11
10.5
50
310
-0.12
-0.63
48
14.0
12
11.4
80
310
-0.12
-0.63
45
13.5
12
11.3
80
310
-0.12
-0.63
42
13.5
12
11.2
80
310
-0.12
-0.63
40
12.8
12
11.1
80
310
-0.12
-0.63
38
12.4
12
10.9
80
310
-0.12
-0.63
35
12.0
12
10.8
80
310
-0.12
-0.63
50
14.2
14
12.6
80
310
-0.12
-0.63
48
13.9
14
12.4
80
310
-0.12
-0.63
45
13.6
14
12.3
80
310
-0.12
-0.63
42
13.1
14
12.1
80
310
-0.12
-0.63
40
12.8
14
11.8
80
310
-0.12
-0.63
38
12.4
14
11.5
80
310
-0.12
-0.63
35
12.6
14
11.3
80
310
-0.12
-0.63
33
11.6
11.6
10.9
80
310
-0.12
-0.63
48
13.8
16
12.9
100
320
-0.11
-0.61
45
13.7
16
12.8
100
320
-0.11
-0.61
42
13.1
16
12.4
100
320
-0.11
-0.61
36
12.2
16
11.6
100
320
-0.11
-0.61
32
11.4
16
10.9
100
320
-0.11
-0.61
45
13.4
17
12.7
120
320
-0.11
-0.60
42
13.0
17
12.4
120
320
-0.11
-0.60
40
12.8
17
12.3
120
320
-0.11
-0.60
38
12.4
17
11.9
120
320
-0.11
-0.60
35
12.0
17
11.5
120
320
-0.11
-0.60
33
11.6
17
11.2
120
320
-0.11
-0.60
30
11.0
17
10.6
120
320
-0.11
-0.60
42
13.0
20
12.5
150
330
-0.11
-0.58
40
12.8
20
12.4
150
330
-0.11
-0.58
38
12.4
20
12.0
150
330
-0.11
-0.58
35
12.0
20
11.6
150
330
-0.11
-0.58
33
11.6
20
11.3
150
330
-0.11
-0.58
30
11.1
20
10.8
150
330
-0.11
-0.58
42
13.0
21
12.5
150
330
-0.11
-0.55
40
12.8
21
12.4
150
330
-0.11
-0.55
38
12.6
21
12.3
150
330
-0.11
-0.55
35
11.9
21
11.5
150
330
-0.11
-0.55
30
11.1
21
10.8
150
330
-0.11
-0.55
38
12.5
25
12.2
180
340
-0.10
-0.55
35
12.0
25
11.6
180
340
-0.10
-0.55
33
11.6
25
11.3
180
340
-0.10
-0.55
30
11.1
25
10.8
180
340
-0.10
-0.55
28
10.6
25
10.4
180
340
-0.10
-0.55
38
12.5
30
12.2
200
360
-0.08
-0.55
35
12.0
30
11.7
200
360
-0.08
-0.55
33
11.6
30
11.4
200
360
-0.08
-0.55
30
11.0
30
10.7
200
360
-0.08
-0.55
28
10.7
30
10.5
200
360
-0.08
-0.55

Typical Physical Properties
Curie Temperature
320 - 380°C
*Coefficient of Thermal Expansion - Perpendicular to magnetization orientation
-1.0 - -3.0 x 10-6 °C-1
*Coefficient of Thermal Expansion - Parallel to magnetization orientation
+5.0 - +8.0 x 10-6 °C-1
Electrical Resistivity
120 - 160 µΩ·cm
Density
7.4 - 7.8 g·cm-3
Vicker's Hardness
550 - 650 HV
Young's Modulus
150 - 170 kN·mm-2
Bending Strength
0.18 - 0.29 kN·mm-2
Compressive Strength
0.8 - 1.0 kN·mm-2
*Due to magnetostriction, all magnetic materials expand/contract at different rates, depending on magnetic orientation.