Bonded Neodymium Magnet

Bonded neodymium magnet is composed of a special form of neodymium powder with a plastic carrier material. They have lower energy product than Sintered neodymium magnet. Very complicated shapes can be produced in Bonded neodymium magnet with very close dimensions.

 

Manufacturing Process

Bonded neodymium magnet is produced by a special form of neodymium powder blended with a plastic carrier material, die pressed and then heated. Parts made in this way can be of complex shapes and come off the tools with close tolerances, requiring no further finish machining.


Machining


Bonded neodymium magnet is easily machined. Coolants must be used while machining this material in order to avoid spontaneous combustion of powder. Machining this material is to remove a layer of protective coating, and re-coating for corrosion resistance may be necessary.


Surface treatment


The corrosion resistance of Bonded neodymium magnet is considered poor, epoxy coating is mostly common used for bonded neodymium magnet.


Magnetizing


Bonded neodymium magnet is isotropic and can be magnetized in any direction or with multiple poles. Special magnetizing fixtures are required in order to achieve multiple pole magnetization, depending on complexity of design and production rate requirements.

 

                    

 

Magnetic properties of Bonded neodymium magnet

 

Grade Residual Induction Coercive Force Intrinsic Coercive Force Maximum Energy Product Maximum Working Temperature
Br Hcb Hcj (BH)max Tw
mT kA/m kA/m kJ/m3
[kGs] [kOe] [kOe] [MGOe]
BNP-3 450-510 199-263 477-597 24-32 100°
[4.5-5.1] [2.5-3.3] [6.0-7.5] [3.0-4.0]
BNP-6 590-650 302-374 597-796 44-53.6 100°
[5.9-6.5] [3.8-4.7] [7.5-10.0] [5.5-7.0]
BNP-8 620-670 390-454 636-796 60-68 100°
[6.2-6.7] 4.9-5.7 [8.0-10.0] [8.0-9.5]
BNP-8SR 620-660 405-470 955-1114 65.6-72 150°
[6.2-6.6] [5.1-5.9] [12.0-14.0] [8.2-9.0]
BNP-9H 650-700 421-484 915-1034 72-80 150°
[6.5-7.0] [5.3-6.1] [11.5-13.0] [9.0-10.0]
BNP-10 680-720 413-477 636-796 76-84 100°
[6.8-7.2] [5.2-6.0] [8.0-10.0] [9.5-10.5]
BNP-11 700-740 430-493 636-796 80-88 100°
[7.0-7.4] [5.4-6.2] [8.0-10.0] [10.0-11.0]
BNP-12L 730-770 366-430 517-637 84-92 90°
[7.3-7.7] [4.6-5.4] [6.5-8.0] [10.5-11.5]

 

Physical properties of Bonded neodymium magnet

 

Grade Density Permeability    Temperature Coefficient of Br Temperature Coefficient of Hc
BNP-3 5.8-6.5g/cm3 1.30μ r  -0.11α(Br) %/ ℃ -0.14α(Hc) %/ ℃
BNP-6 5.8-6.3g/cm3 1.30μ r  -0.11α(Br) %/ ℃ -0.14α(Hc) %/ ℃
BNP-8 5.8-6.2g/cm3 1.20μ r  -0.11α(Br) %/ ℃ -0.14α(Hc) %/ ℃
BNP-8SR 5.8-6.2g/cm3 1.16μ r  -0.07α(Br) %/ ℃ -0.09α(Hc) %/ ℃
BNP-9H 5.8-6.2g/cm3 1.16μ r  -0.07α(Br) %/ ℃ -0.09α(Hc) %/ ℃
BNP-10 5.8-6.2g/cm3 1.20μ r  -0.11α(Br) %/ ℃ -0.11α(Hc) %/ ℃
BNP-11 5.8-6.2g/cm3 1.20μ r  -0.11α(Br) %/ ℃ -0.11α(Hc) %/ ℃
BNP-12L 5.8-6.2g/cm3 1.20μ r  -0.08α(Br) %/ ℃ -0.26α(Hc) %/ ℃