Super strong neodymium magnets

- Nov 07, 2017 -

NdFeB magnet

     neodymium rare earth magnet as a sunrise industry, energy saving and environmental protection, has been widely used in information technology, automotive, nuclear magnetic resonance, wind power and electrical fields, the expected 3-5 years compound growth rate of about 20%. As China has obvious resources, costs and market advantages, the world NdFeB industry is shifting to China. In 2005, China's NdFeB production accounted for more than 70% of the global output.


Sinterd Neodymium Magnets and bonded NdFeB two.


neodymium iron boron

Definition of terms

Main magnetic properties:


Including remanence (Br), magnetic coercivity (Hcj) magnetic coercivity (Hcb), maximum energy product ((BH) max)


Auxiliary magnetic properties:


Including permanent magnetic material relative recovery permeability (μrec), temperature coefficient of remanence (α (Br)), magnetic susceptibility coercivity temperature coefficient (α (Hcj)), Curie temperature (Tc)

Classification grades

Material Category:


Sintered NdFeB permanent magnet materials according to the degree of coercivity magnetic coercivity is divided into low coercivity N, moderate coercivity M, high coercivity H, high coercivity SH, high coercivity UH, pole High coercivity EH six products




Each type of product according to the maximum energy product size divided by a number of grades


N35-N52, N35M-N50M, N30H-N48H, N30SH-N45SH, N28UH-N35UH, N28EH-N35EH


Number brand:


Grade Example: 048021 represents a sintered NdFeB permanent magnetic material with (BH) max of 366 to 398 kJ / m and Hcj of 800 kA / m.


Character grades:


Sintered Nd-Fe-B permanent magnet material grades by the Lord said the two kinds of magnetic properties of three parts, the first part of the main said by the neodymium chemical symbol ND, the chemical element of the iron symbol FE and boron chemical composition B, the first The two parts are the numbers before the line, which is the nominal value (in kj / m) of the maximum energy product (BH) max of the material and the figure after the slash, the coercivity value of the magnetic polarization (in KA / m) one tenth of the value rounding rounded.


Examples of grades: NdFeb380 / 80 represents a sintered NdFeB permanent magnetic material with (BH) max of 366 to 398 kj / m and Hcj of 800 kA / MR.

chemical composition

NdFeB permanent magnet material is based on the intermetallic compound RE2FE14B permanent magnet material. The main components of rare earth (RE), iron (FE), boron (B). Among them, rare earth ND may be replaced by other rare earth metals, such as Dy and Pr, for the purpose of obtaining different properties. Iron may also be replaced by other metal components such as cobalt (Co) and aluminum (Al) But plays an important role in forming intermetallic compounds of tetragonal crystal structure. The compounds have high saturation magnetization, high uniaxial anisotropy and high Curie temperature.

Manufacturing process

Sintered Nd-Fe-B permanent magnet material is used in powder metallurgy process, the alloy after melting made of powder and pressed into a magnetic field in the pressure of the embryo, the pressure in the inert gas or vacuum sintering to achieve densification, in order to improve the coercivity of the magnet , Usually require aging heat treatment.

Material application

Sintered NdFeB permanent magnet materials with excellent magnetic properties, widely used in electronics, electrical machinery, medical equipment, toys, packaging, hardware machinery, aerospace and other fields, the more common permanent magnet motors, speakers, magnetic separator, Computer disk drives, magnetic resonance imaging equipment and meters.


Bonded NdFeB Magnet


Product Description: Manufactured by powder metallurgy.


Chemical composition: Nd2Fe14B


High remanence, high coercivity, high energy product, high cost performance.


Surface coating or plating corrosion resistance is low.


Easy to process a variety of sizes and minimum specifications, are widely used in various fields.


NdFeB bonded permanent magnet material is made of NdFeB magnetic powder added to the binder. Since the successful development of this material in 1988, Japan has developed a considerable speed of sound and its output has multiplied. As a high-performance permanent magnet material, Japan is in line with the trend of short, small, light and thin electronic products.


Bonded NdFeB permanent magnet materials production and application development late, the application is not widely used, less dosage, mainly for office automation equipment, electrical equipment, audio-visual equipment, instrumentation, small motors and metering machinery, mobile phones , CD-ROM, DVD-ROM drive motor, hard disk spindle motor HDD, other micro DC motors and automated instrumentation and other fields widely used. In recent years, China's bonded NdFeB permanent magnet material applications are: computer accounted for 62%, electronics industry accounted for 7%, office automation equipment accounted for 8%, automotive accounted for 7%, appliances accounted for 7%, others accounted for 9%.


Compared with sintered magnets, it can be formed once, without secondary processing, can be made of a variety of complex shape magnets, which is unsurpassed sintered magnets, the use of it can greatly reduce the size and weight of the motor.

Article from NdFeB Industry Network

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