ferrite magnet

Permanent magnet made of SrO or Bao and Fe2O3
Ferrite magnet is a kind of permanent magnet mainly made of SrO or Bao and Fe2O3. Compared with other permanent magnets, ferrite magnets are hard and brittle with low magnetic energy. However, it is not easy to demagnetize and corrode, the production process is simple and the price is low. Therefore, ferrite magnets have the highest output in the whole magnet industry and are widely used in industrial production.

Permanent magnet made of SrO or Bao and Fe2O3

Ferrite magnet is a kind of permanent magnet mainly made of SrO or Bao and Fe2O3. Compared with other permanent magnets, ferrite magnets are hard and brittle with low magnetic energy. However, it is not easy to demagnetize and corrode, the production process is simple and the price is low. Therefore, ferrite magnets have the highest output in the whole magnet industry and are widely used in industrial production.

Material introduction

Ferrite magnet is a kind of sintered permanent magnetic material, which is composed of barium and strontium ferrite. This kind of magnetic material has the advantages of strong anti demagnetization and low cost. Ferrite magnets are hard and brittle, requiring special machining processes. Since its anisotropic magnet is oriented along the manufacturing direction, it must be magnetized along the selected direction, while its isotropic magnet is not oriented, it can be magnetized in any direction, although a slightly stronger magnetic induction is often found on the smallest side of the pressure surface. The magnetic energy product ranges from 1.1mgoe to 4.0mgoe. Because of its low cost, ferrite magnets have a wide range of applications, from motors, speakers to toys and handicrafts, so they are the most widely used permanent magnet materials at present.

Material characteristics

It is produced by powder metallurgy with low remanence and low magnetic permeability. It has high coercive force and strong anti demagnetization ability, and is especially suitable for magnetic circuit structure under dynamic working conditions. The material is hard and brittle, and can be used for cutting with emery tools. The main raw material is oxide, so it is not easy to corrode. Working temperature: - 40 ℃ to + 200 ℃.
Ferrite magnets are divided into various anisotropy (anisotropy) and isotropy (isotropy). The magnetic properties of isotropic sintered ferrite permanent magnetic materials are weak, but they can be magnetized in different directions of the magnet; Anisotropic sintered ferrite permanent magnetic materials have strong magnetic properties, but can only be magnetized along the predetermined magnetization direction of the magnet.

physical property

In the actual production of ferrite magnets, raw materials with good chemical composition may not be able to obtain ferrite magnets with good performance and microstructure sometimes, because of the influence of physical properties. The physical properties of iron oxide listed include average particle size APS, specific surface area SSA and bulk density BD. Since iron oxide accounts for about 70% in the formulation of manganese zinc ferrite magnet, its APS value has a great influence on the APS value of ferrite magnet powder. Generally speaking, the APS value of iron oxide is small, and the APS value of ferrite magnet powder is also small, which is conducive to speeding up the chemical reaction. However, considering that the powder particles are too fine, which is not conducive to the subsequent pressing and easy crystallization during sintering, the APS value should not be too small. Obviously, when the APS value of iron oxide is too large, the diffusion reaction of spinel phase can only be carried out due to the large particle size during pre sintering, and the grain growth process cannot be further carried out. This inevitably leads to an increase in the activation energy required for sintering, which is not conducive to the solid-state reaction.  

Performance table

Main performance grade parameters of sintered permanent ferrite magnets

牌号Grade	剩磁(Br)		磁感矫顽力(HcB)		内禀矫顽力(HcJ)		最大磁能积(BH)max
	mT	KGauss	KA/m	KOe	KA/m	KOe	KJ/m3	MGOe
Y8T	200~235	2.0~2.35	125-160	1.57-2.01	210-280	2.64-3.51	6.5-9.5	0.8-1.2
Y22H	310~360	3.10~3.60	220-250	2.76-3.14	280-320	3.51-4.02	20.0-24.0	2.5-3.0
Y25	360~400	3.60~4.00	135-170	1.70-2.14	140-200	1.76-2.51	22.5-28.0	2.8-3.5
Y26H-1	360~390	3.60~3.90	200-250	2.51-3.14	225-255	2.83-3.20	23.0-28.0	2.9-3.5
Y26H-2	360~380	3.60~3.80	263-288	3.30-3.62	318-350	3.99-4.40	24.0-28.0	3.0-3.5
Y27H	350~380	3.50~3.80	225-240	2.83-3.01	235-260	2.95-3.27	25.0-29.0	3.1-3.6
Y28	370~400	3.70~4.00	175-210	2.20-3.64	180-220	2.26-2.76	26.0-30.0	3.3-3.8
Y28H-1	380~400	3.80~4.00	240-260	3.01-3.27	250-280	3.14-3.52	27.0-30.0	3.4-3.8
Y28H-2	360~380	3.60~3.80	271-295	3.40-3.70	382-405	4.80-5.08	26.0-30.0	3.3-3.8
Y30H-1	380~400	3.80~4.00	230-275	2.89-3.46	235-290	2.95-3.64	27.0-32.5	3.4-4.1
Y30H-2	395~415	3.95~4.15	275-300	3.45-3.77	310-335	3.89-4.20	27.0-32.0	3.4-4.0
Y32	400~420	4.00~4.20	160-190	2.01-2.39	165-195	2.07-2.45	30.0-33.5	3.8-4.2
Y32H-1	400~420	4.00~4.20	190-230	2.39-2.89	230-250	2.89-3.14	31.5-35.0	3.9-4.4
Y32H-2	400~440	4.00~4.40	224-240	2.81-3.01	230-250	2.89-3.14	31.0-34.0	3.9-4.3
Y33	410~430	4.10~4.30	220-250	2.76-3.14	225-255	2.83-3.20	31.5-35.0	3.9-4.4
Y33H	410~430	4.10~4.30	250-270	3.14-3.39	250-275	3.14-3.45	31.5-35.0	3.9-4.4
Y34	420~440	4.20~4.40	200-230	2.51-2.89	205-235	2.57-2.95	32.5-36.0	4.1-4.4
Y35	430~450	4.30~4.50	215-239	2.70-3.00	217-241	2.73-3.03	33.1-38.2	4.1-4.8
Y36	430~450	4.30~4.50	247-271	3.10-3.40	250-274	3.14-3.44	35.1-38.3	4.4-4.8
Y38	440~460	4.40~4.60	285-305	3.58-3.83	294-310	3.69-3.89	36.6-40.6	4.6-5.1
Y40	440~460	4.40~4.60	330-354	4.15-4.45	340-360	4.27-4.52	37.6-41.8	4.7-5.2

Main performance grade parameters of bonded permanent ferrite magnets

牌号Grade	剩磁(Br)		磁感矫顽力(HcB)		内禀矫顽力(HcJ)		最大磁能积(BH)max
	mT	KGauss	KA/m	KOe	KA/m	KOe	KJ/m3	MGOe
YN1T	63-83	0.63-0.83	50-70	0.63-0.88	175-210	2.20-2.64	0.8-1.2	0.1-0.15
YN4H	135-155	1.35-1.55	85-105	1.07-1.32	175-210	2.20-2.64	3.2-4.5	0.4-0.56
YN4TH	150-180	1.50-1.80	95-120	1.19-1.38	180-230	2.26-2.89	3.8-5.5	0.48-0.69
YN6T	180-220	1.80-2.20	120-140	1.28-1.76	175-200	2.20-2.51	5.0-7.0	0.63-0.88
YN10	220-240	2.20-2.40	145-165	1.82-2.07	190-225	2.39-2.83	9.2-10.6	1.15-1.33
YN10H	220-250	2.20-2.50	150-200	1.88-2.51	190-220	2.39-2.76	9.2-11.0	1.15-1.38
YN11	230-250	2.30-2.50	160-185	2.01-2.32	225-260	2.83-3.27	10.0-12.0	1.25-1.5
YN12	240-250	2.40-2.50	140-160	1.76-2.01	200-230	2.51-2.89	11.4-13.6	1.43-1.7