Introduction ：Neodymium Magnets, also known as NdFeB, NIB, or Neo magnets, are the most widely-used type of rare earth magnets. It is the strongest type of permanent magnet made from an alloy of Neodymium, Iron, and Boron with the Nd2Fe14B tetragonal crystalline structure. It has replaced other types of magnets in many applications in modern products that require strong permanent magnets, such as motors in cordless tools, hard disk drives, and magnetic fasteners.

Sintering NdFeB Magnets:

physical properties of Sintering NdFeB Magnets

Parameter	unit	Parameter range
Curie temperature	℃	320-395
Maximum working temperature	℃	70-250
Electrical resistivity	KΩ.cm	120-160
Thermal conductivity	W/M.C	7.0-10
Hardness	HV	560-650
Density	G/Cm3	7.4-7.7
Relative Recoil Permeability		1.02-1.08
Saturation Magnetization	KOe	30-40
Temperature Coefficient of Remanence	%/℃(20℃-250℃	-(0.08-0.12)
Temperature Coefficient of iHc	%/℃(20℃-250℃	-(0.34-0.75)
Compression Strength	N/Mm2	1000-1300
Flexural Strength	N/Mm2	250-400
Young modulus	KN/Mm2	150-160
Elongation	%	~0

MAGNETIC CHARACTERISTICS OF SINTERED NdFeb

Production Process of Sintering NdFeB Magnets

GRADE	(Br)		(bHc)		(iHc)		(BH)max		Tw ℃
GRADE	T	KGs	KA/m	KOe	KA/m	KOe	KJ/m3	MGOe	Tw ℃
N35	1.18-1.23	11.8-12.3	≥868	≥10.9	≥955	≥12	263-287	33-36	≤80
N38	1.22-1.28	12.2-12.8	≥899	≥11.3	≥955	≥12	287-310	36-39	≤80
N40	1.26-1.31	12.6-13.1	≥923	≥11.6	≥955	≥12	302-326	38-41	≤80
N42	1.28-1.34	12.8-13.4	≥923	≥11.6	≥955	≥12	318-342	40-43	≤80
N45	1.32-1.37	13.2-13.7	≥876	≥11.0	≥955	≥12	342-366	43-46	≤80
N48	1.36-1.42	13.6-14.2	≥836	≥10.5	≥876	≥11	358-390	45-48	≤80
N50	1.39-1.45	13.9-14.5	≥836	≥10.5	≥876	≥11	374-406	48-51	≤80
N52	1.42-1.48	14.2-14.8	≥796	≥10.0	≥876	≥11	390-422	49-53	≤80
N35M	1.18-1.23	11.8-12.3	≥868	≥10.9	≥1114	≥14	263-287	33-36	≤100
N38M	1.22-1.28	12.2-12.8	≥899	≥11.3	≥1114	≥14	287-310	36-39	≤100
N40M	1.26-1.31	12.6-13.1	≥923	≥11.6	≥1114	≥14	302-326	38-41	≤100
N42M	1.28-1.34	12.8-13.4	≥923	≥11.6	≥1114	≥14	318-342	40-43	≤100
N45M	1.34-1.39	13.4-13.9	≥876	≥11.0	≥1114	≥14	342-366	43-46	≤100
N48M	1.36-1.42	13.6-14.2	≥876	≥11.0	≥1114	≥14	366-390	46-49	≤100
N35H	1.18-1.23	11.8-12.3	≥868	≥10.9	≥1353	≥17	263-287	33-36	≤120
N38H	1.22-1.28	12.2-12.8	≥899	≥11.3	≥1353	≥17	287-310	36-39	≤120
N40H	1.26-1.31	12.6-13.1	≥923	≥11.6	≥1353	≥17	302-326	38-41	≤120
N42H	1.28-1.34	12.8-13.4	≥923	≥11.6	≥1353	≥17	318-342	40-43	≤120
N45H	1.33-1.39	13.3-13.9	≥923	≥11.6	≥1353	≥17	342-366	43-46	≤120
N48H	1.36-1.42	13.6-14.2	≥923	≥11.6	≥1274	≥16	366-390	46-49	≤120
N33SH	1.14-1.19	11.4-11.9	≥836	≥10.5	≥1592	≥20	247-270	31-34	≤150
N35SH	1.18-1.23	11.8-12.3	≥868	≥10.9	≥1592	≥20	263-287	33-36	≤150
N38SH	1.22-1.28	12.2-12.8	≥899	≥11.3	≥1592	≥20	287-310	36-39	≤150
N40SH	1.26-1.31	12.6-13.1	≥923	≥11.6	≥1592	≥20	302-326	38-41	≤150
N42SH	1.28-1.34	12.8-13.4	≥923	≥11.6	≥1592	≥20	318-342	40-43	≤150
N45SH	1.33-1.39	13.3-13.9	≥923	≥11.6	≥1592	≥20	342-366	43-46	≤150
N28UH	1.03-1.09	10.3-10.9	≥780	≥9.80	≥1990	≥25	207-231	26-29	≤180
N30UH	1.09-1.14	10.9-11.4	≥812	≥10.2	≥1990	≥25	223-247	28-31	≤180
N33UH	1.13-1.17	11.3-11.7	≥852	≥10.7	≥1990	≥25	247-263	31-33	≤180
N35UH	1.18-1.22	11.8-12.2	≥868	≥10.9	≥1990	≥25	263-287	33-36	≤180
N38UH	1.22-1.27	12.2-12.7	≥899	≥11.3	≥1990	≥25	287-310	36-39	≤180
N28EH	1.03-1.09	10.3-10.9	≥780	≥9.80	≥2388	≥30	207-231	26-29	≤200
N30EH	1.08-1.13	10.8-11.3	≥812	≥10.2	≥2388	≥30	223-247	28-31	≤200
N33EH	1.13-1.17	11.3-11.7	≥852	≥10.7	≥2388	≥30	247-263	31-33	≤200
N35EH	1.18-1.22	11.8-12.2	≥868	≥10.9	≥2388	≥30	263-287	33-36	≤200
N28AH	1.03-1.09	10.3-10.9	≥780	≥9.80	≥2786	≥35	207-231	26-29	≤220
N30AH	1.08-1.13	10.8-11.3	≥812	≥10.2	≥2786	≥35	223-247	28-31	≤220

Sintering NdFeB Magnets Curves Diagram

Bonded NdFeB Magnets:

Physical properties of Bonded NdFeB Magnets

Parameter	unit	Injection bonded ferrite magnet				Bonded NiFeB magnet
Parameter	unit	PBF-10	PBF-11	PBF-13	PBF-15P	BN-6	PBN-8P	BN-10	PBN-12	PBN-8H
Curie temperature	℃	450				310	310	310	310	310
Maximum working temperature	℃	120				140	140	110	130	150
Density	g/cm3	3.4-3.7				5.8-6.2	5.8-6.2	5.8-6.2	6.2-6.4	5.8-6.2
Recoil Permeability	urec	1.3				1.15	1.15	1.22	1.22	1.15
Saturation magnetization	kOe	10				>25	>25	>25	>25	>40
Saturation magnetization	kA/m	800				>=2000	>=2000	>=2000	>=2000	>=2000
Temperature Coefficient of Br	%/℃	-0.2				-0.13	-0.13	-0.07~	-0.13	-0.07~
Temperature Coefficient of Br	%/℃	-0.2				-0.13	-0.13	-0.15	-0.13	-0.15

Size Range of Bonded NdFeB Magnets

Shape

Schematic Diagram

Grade

Range

Dic

N42

D<=150 H<=60 mm B/H<=20

Radial Dic

42H

N52

D<=80 H<=60 mm B/H<=20

Block

N42

L<=200 mm

42SH

W<=80 mm

N50

L/W<=20, L/H<=20

N52

H<=80 mm

Ring

Axial ring

N42

D<=150 mm d>=1 mm

(D-d)/2 >-=1.4 mm, d/D <=0.8

D/35<= H<=1.5 mm, H<=60 mm

Radial ring

D<=150 mm d>=1 mm

(D-d)/2 >-=1.4 mm, d/D <=0.8

D/35<= H<=1.5 mm, H<=60 mm

Arc

Tile

N42

L<=200 mm W<=80, H<=80

1.5 mm <= T <= 60 mm

L/W<= 10, L/H<= 10 ,α<=180

Tile

N42SH

W<=150 , H<=80

1mm <= T <= 60 mm

W/H<= 5 mm, W/T<= 30mm

Bread shape

N50

L<=200 mm

W<=80 mm

L/W<=20, L/H<=20

N52

H<=80 mm

Sphere

N42

Countersunk

N42

N52

Bonded NdFeB Magnets Curves Diagram

Neodymium Magnet Surface Treatments

1. Painting, coating, or plating is generally recommended for NdFeB.

2. Neo magnets can also be plated using ion vacuum deposition (IVD) techniques. This specialty plating is very controllable for thickness and has excellent adhesion to the material.

3. Nickel, zinc, or tin plating provides good corrosion resistance for NdFeB magnets, though longer lead times or higher volumes may be required for these.

4. Organic coatings exhibits good corrosion resistance characteristics, it is successfully developed for NdFeB. For especially harsh environments, it may be advisable to use a combination of coating techniques, or to encapsulate the material in a sealed housing.

Special Remarks

1. NdFeB powder is very fine and when dry can ignite spontaneously, special care must be taken when handling NdFeB powder.

2. NdFeB magnets are very powerful, special care must be taken in handling these magnets to avoid injuries.

3. NdFeB magnets are susceptible to corrosion.

NdFeB Magnets Materials