Bonded NdFeB magnet features: 1. Magnetic property between sintered NdFeB magnet and ferrite magnet, it is a high performance isotropic permanent magnet with good consistency and stability.2. Can be made into permanent magnets of small sizes, complex shapes and high geometric accuracy with press moulding and injection moulding. Easy to achieve large-scale automated production.3. Can be magnetized via any direction. Multi poles or even countless poles can be realized in bonded NdFeB. 4. Bonded NdFeB magnets are widely used in all kinds of micro motors, such as spindle motor, synchronous motor, stepper motor, DC motor, brushless motor, etc.Magnetic Characteristics and Physical Properties of Bonded Compression Injection Moulding NdFeB
Grade
SYI-3
SYI-4
SYI-5
SYI-6
SYl-7
SYI-6SR(PPS)
Residual Induction (mT) (KGs)
350-450
400-500
450-550
500-600
550-650
500-600
(3.5-4.5)
(4.0-5.0)
(4.5-5.5)
(5.0-6.0)
(5.5-6.5)
(5.0-6.0)
Coercive Force (KA/m) (KOe)
200-280
240-320
280-360
320-400
344-424
320-400
(2.5-3.5)
(3.0-4.0)
(3.5-4.5)
(4.0-5.0)
(4.3-5.3)
(4.0-5.0)
Intrinsic Coercive Force (KA/m) (KOe)
480-680
560-720
640-800
640-800
640-800
880-1120
(6.5-8.5)
(7.0-9.0)
(8.0-10.0)
(8.0-10.0)
(8.0-10.0)
(11.0-14.0)
Max. Energy Product (KJ/m3) (MGOe)
24-32
28-36
32-48
48-56
52-60
40-48
(3.0-4.0)
(3.5-4.5)
(4.5-6.0)
(6.0-7.0)
(6.5-7.5)
(5.0-6.0)
Permeability (μH/M)
1.2
1.2
2.2
1.2
1.2
1.13
Tempetrature Coefficient (%/℃)
-0.11
-0.13
-0.13
-0.11
-0.11
-0.13
Curie Temperature (℃)
320
320
320
320
320
360
Max.Work Temperature (℃)
120
120
120
120
120
180
Magnetizing Force (KA/m) (KOe)
1600
1600
1600
1600
1600
2000
20
20
20
20
20
25
Dendity (g/m3)
4.5-5.0
4.5-5.0
4.5-5.1
4.7-5.2
4.7-5.3
4.9-5.4
It has four production methods, the first is pressing molding. (The magnetic powder and the adhesive are mixed evenly in a volume ratio of about 7:3, rolled to the required thickness and then solidified to make a finished product), the second is injection molding. (Mix the magnetic powder with the binder, heat and knead, pre-granulate, dry, and then send the spiral guide rod to the heating room for heating, inject it into the mold cavity for molding to get the finished product after cooling), the third is extrusion molding. (It is basically the same as the injection molding method, the only difference is that after heating, the pellets are extruded into the mold through a cavity for continuous molding), and the fourth is compression molding(Mix the magnetic powder and binder according to the ratio, granulate and add a certain amount of coupling agent, press into the mold, solidify at 120°~150°, and finally get the finished product.)The disadvantage is that the bonding NdFeB starts late, and the magnetic properties are weak, besides, the application level is narrow, and the dosage is also small.Its advantages are high remanence, high coercive force, high magnetic energy product, high performance-price ratio, one-time forming without secondary processing, and can be made into various complex-shaped magnets, which can greatly reduce the volume and weight of the motor. And it can be magnetized in any direction, which can facilitate the production of multi-pole or even infinite pole overall magnets.It is mainly used in office automation equipment, electrical equipment, audio-visual equipment, instrumentation, small motors and measuring machinery, mobile phone vibration motors, printer magnetic rollers, power tool hard disk spindle motors HDD, other micro DC motors and automation instruments.