2014年8月25日星期一

The Use of NdFeB Magnet by china-magnets-source-material.com

Here, let’s introduce the use of NdFeB magnet in the market.

As the third generation permanent magnet material, NdFeB magnet has rather high properties. The NdFeB magnets apply to the industries for energy sources, transportation, machinery, medical treatment, IT, and home appliance. Especially with the development of information technology, it brings so many new uses for the NdFeB magnets.

In the electro-acoustic industry, the loudspeaker, receiver, microphone, annunciator all are using NdFeB.

In the electrical machine industry, they also can’t work without NdFeB magnet, such as VCM, CDDVD-ROM, dynamo, electromotor, micro machine, ac motor and so on.

In conclusion, it is a new sight to use more and more NdFeB products in our modern daily life.

Neodymium Rare Earth Magnets by china-magnets-source-material.com

Neodymium-Iron-Boronpermanent Magnet is also named as Neodymium Rare Earth Magnet, which contains rare earth metal. The Neodymium Rare Earth Magnets have powerful magnetic force. Its chemical formula is Nd2Fe14B, is a kind of man-made magnet. Until now, the Neodymium Rare Earth Magnets is the most powerful permanent magnet in the world.

In the coming two decades, there is no magnetic material which can replace the Neodymium Rare Earth Magnet. The main raw materials are rare earth metal Neodymium, pr, pure iron, aluminum, boron, and other rare earth material.

The core technology of Neodymium Rare Earth Magnet is mainly reflected in manufacturing. The advantage of Neodymium Rare Earth Magnets products is strong magnetic force, high consistency of magnetic force, high coercive force and so on. 


Cast Alnico by china-magnets-source-material.com

According to the productive technology, the alnico divides into Sintered Alnico and Cast alnico. There are round, rectangle, segment, and different irregular shapes. It can be manufactured into different sizes and shapes by casting technique. Comparing to casting technique, the Sintered magnets products are limited in small size. The tolerance of semi-finished product of Sintered Alnico is better than the semi-finished product of Cast Alnico, but the magnetic properties is lower than Cast alnico.

The advantage of Cast alnico is high in remanence (max 1.35T), low in temperature coefficient (T.C.), and the highest temperature can be 550°C. However, what is the disadvantage of Cast alnico? Its coercive force is very small. The demagnetizing curve of cast alnico is irregular. Therefore, the cast alnico is easy to magnetize, and easy to demagnetize in the same way.

ALNiCo Magnet by china-magnets-source-material.com

Alnico magnet is the first generation permanent magnetic material. It is a kind of alloy that contains aluminum, nickel, cobalt, iron and other microscope metallic element.

The Alnico magnet manufacture successfully in the 1930 s. At that time, the Alnico is the best in magnetic performance, and its temperature coefficient is very small. Therefore, the Alnico magnet is mainly used on producing the permanent motor at that time. After the 1960s, with the development of ferrite permanent magnet and rare earth permanent magnet, the alnico magnets are replaced to use in producing motor.

SmCo Magnets by china-magnets-source-material.com

SmCo magnet is a kind of rare earth magnets. According to different compositions, it is divided into SmCo5 and Sm2Co17. Sm1Co5 came out first, and then Sm2Co17. The price of SmCo magnet is very expensive for its raw material is very scarce. This limits its development.
 
SmCo magnet, as the second generation of rare earth magnets, is not only high in magnetic energy and coercive force, but also good for temperature characteristic. Comparing with the neodymium magnets, the SmCo magnet is more suitable for working in the environment with high temperature.

Magnetic Therapy Products by china-magnets-source-material.com

With magnet further study, the use of permanent magnet material in biological treatment health care become widely. There are more and more magnetic therapy products appeared in market, such as magnetic back support, magnetic elbow, and magnetic insoles and so on. All these products use very small magnets which can regulate your blood circulation.
 

How magnets connect with letter pigeon? By china-magnets-source-material.com

Magnet material also brings us many unexpected pleasure.
We all know letter pigeons, but seldom person know why the letter pigeons are good at recognizing the road to home. If let the pigeons fly away for hundreds of kilometer, they still can get home safe.

Why the pigeons can do this?

In fact, the pigeons are sensitive to earth magnetic field. They can estimate and position themselves by the strong and weak of earth magnetic field in the different place. If we bind magnet on the head of the pigeons, they will disorientation. If they overfly radio towers, powerful electromagnetic interference will also make them become disoriented.

How to choose a magnetic material? By china-magnets-source-material.com

When choose a magnet material, you need to figure out the requirement you need magnet to do in your application, but not blindly pursue high performance magnetic material; and then get a comprehensive understanding of different magnetic materials. If you have confusion on some point, you can ask for technical help from magnet specialist or manufacturer.

Material
Magnetic Property
Working Temperature
Corrosion Resistance
Price
Remark
NdFeB Magnet
high
low
low
high
1
Ferrite / Ceramic
middle
middle
high
low
3
SmCo Magnet
high
high
high
high
2
AlNiCo Magnet
low
high
high
middle
4

Ferrite and ndfeb magnet can be processed by sintering or bonding method. The Sintered magnet has high magnetic force, but poor formation. The bonded magnet has good formation, but low property.
Alnico can be processed by casting and sintering, the cast alnico has high property, but poor formation. The bonded alnico has good formation, but low property.

This is a brief introduction for choosing magnetic material, for more information, please visit our website www.china-magnets-source-material.com

2014年8月22日星期五

The magnetic field orientation for permanent magnet by china-magnets-source-material.com

Orientation direction: The direction where anisotropic magnets can obtain the best magnetic property.

Permanent magnets are divided into two types: Isotropic and Anisotropic.

Isotropic magnet: The magnet has same magnetic property in any direction.

Anisotropic magnet: The magnet has different magnetic property in different direction. And there is one orientation which can obtain the best magnetic property.



Sintered NdFeB magnet is anisotropic magnet. So the orientation (magnetized direction) should be decided before production.

Bonded NdFeB magnet is Isotropic magnet. If you buy uncharged magnet, there is no necessary to confirm magnetization direction.

How long can magnetic force of NdFeB magnet last? By china-magnets-source-material.com

 
That means it doesn't lose its magnetic force and change magnetic property under ordinary circumstances. 
 
We assume that the environment is stable, it’s just few lose on magnetic force even after a long time use. 
So in an actual application, we can ignore the influence of time factor on magnetic force.

The composition of Neodymium Magnet by china-magnets-source-material.com

Neodymium IronBoron Magnet contains rare earth metals like neodymium (Nd), metallic element iron (Fe), non-metallic element boron (B) and little trace elements, such as dysprosium (Dy), terbium (Tb), cobalt ( Co), niobium (Nb), gallium (Ga), aluminum(Al), copper (Cu), etc. 
 
Neodymium Iron Boron Magnet is based on compound Nd2Fe14B. The molecular formula is similar with Nd2Fe14B. But the magnetic force will be very low or even no magnetic force with exact proportion of Nd2Fe14B. Only when the content of neodymium (Nd) and boron (B) in magnet is higher than nd and B in Nd2Fe14B, it can obtain better magnetic properties.

2014年8月21日星期四

The grade explanation for Sintered Neodymium Magnet by china-magnets-source-material.com

N: general coercive force Hcj 12Koe, for example: N40
M: medium coercive force Hcj 14Koe, for example: N48M
H: high coercive force Hcj 17Koe, for example: N45H
SH: very high coercive force Hcj 20Koe, for example: N42SH
 
UH: great high coercive force Hcj 25Koe, for example: N438UH
EH: super high coercive force Hcj 30Koe, for example: N35EH
 
AH: Top high coercive force Hcj 35Koe, for example: N28AH
T: high requirement for corrosion resistance, for example: N45T
L-T: low temperature coefficient and high requirement for corrosion resistance, for example: L-38SHT

PS: Figure represents the max energy product

Magnetic Property Parameter transformation by china-magnets-source-material.com

Description
Abbreviation
Unit SI
Unit CGS
CGS / SI
Remanence
Br
T
kGs
10
Coercive force
Hcb
KA/m
kOe
4π/10³
Intrinsic coercive field
Hcj,Hic
KA/m
kOe
4π/10³
Magnetic energy product
BH max
KJ/m³
MGOe
4π/10³
Magnetic force on Surface
H
KA/m
kOe
4π/10³
Magnetic flow
φ
Wb, Vs
Mx
108
Magnetic moment
Mm
A.m ²
Vs.cm
10³
Magnetization intensity
M
T
kGs
10

Note: Gs and Oe are the same numerical value, but two different physical significance units. So the magnetic field is the same by 1 Gs and 1 Oe.
103/4π=79.6