The Strongest Permanent Magnet In The World Today—Neodymium (NdFeB) Magnet
NdFeB magnet, which is the most commercialized magnet, is known as the king of magneto. It has the characteristics of small volume, light weight and strong magnetic properties. It is the best performance and price ratio magnet so far. With its extremely high magnetic properties, its maximum magnetic energy product (BHmax) is over 10 times higher than that of ferrite (Ferrite). Its own mechanical processing performance is also quite good. The working temperature is up to 200 degrees centigrade. Moreover, its texture is hard, its performance is stable, and its cost performance is very good, so its application is extremely extensive. But because of its strong chemical activity, the surface layer must be treated.
The Basic Common Sense of NdFeB Magnet
NdFeB magnets can be divided into two types: Bonded NdFeB and sintered NdFeB.
It is not expected that in the next 20-30 years, magnetic materials will replace neodymium iron boron magnets. The main raw materials for producing NdFeB magnets are neodymium, pure iron, ferroboron, and other additives. The core technology of the NdFeB magnet industry is mainly embodied in the manufacturing process, which is embodied in the uniformity, consistency, and quality of the processing, and the neodymium magnets coating.
As the third-generation rare earth permanent magnet, the Nd-Fe-B magnet has a high performance and price ratio. It is widely used in energy, transportation, machinery, medical, IT, household electrical appliances, and other industries, especially with the development of information technology as the representative of the knowledge economy, which brings new uses to the rare earth permanent magnet, NdFeB industry, and other functional materials. It brings a broader market prospect for the NdFeB industry.
Types of NdFeB Magnets: Sintered vs. Bonded
Although both types are made using the same neodymium-iron-boron alloy, their fabrication processes give rise to notable variations in performance characteristics, physical properties, and uses.
Sintered NdFeB Magnets
The magnetic performance of sintered magnets is top-notch, with energy products ranging from 30 to 52 MGOe. The magnets retain magnetic strength in high temperatures, where the maximum operating temperatures reach up to 220°C, depending on the type. Sintered magnets are relatively fragile and lack adequate corrosion protection, hence the need for coatings such as nickel or zinc.
Bonded NdFeB Magnets
The presence of polymers in bonded magnets reduces the concentration of the magnetic powder, which translates to reduced energy products ranging from 5 to 12 MGOe. The operating temperature of bonded magnets is restricted by the polymer binder, with temperatures between 80 and 150°C. The polymer binder adds more mechanical strength and flexibility, thus making bonded magnets less susceptible to chipping or fracturing. Moreover, the binder provides self-protection against corrosion.
Sintered NdFeB Magnets vs. Bonded NdFeB Magnets
|
Property |
Sintered NdFeB |
Bonded NdFeB |
|
Magnetic strength (BHmax) |
High (30–52 MGOe) |
Low to medium (5–12 MGOe) |
|
Maximum operating temperature |
80–220°C (grade dependent) |
80–150°C (binder dependent) |
|
Mechanical properties |
Brittle, hard |
Tough, flexible |
|
Shape complexity |
Simple shapes (blocks, discs, rings) |
Complex, net shapes possible |
|
Dimensional tolerance |
Requires secondary grinding |
Tight as-molded |
|
Corrosion resistance |
Poor; requires coating |
Good due to binder |
|
Production volume |
Low to medium |
High |
|
Cost per magnet (high volume) |
Higher |
Lower |
The Application of NdFeB Magnets In Medical Treatment
NdFeB permanent magnet is a kind of high-tech material. It can generate a biological magnetic field simulating the characteristics of the human body's magnetic field, and the performance is stable. The human body can rectify the magnetic field of the human body, and promote the operation of the meridian, increase the blood supply and supply of the brain, reduce the excitement of the peripheral nerve of the cerebral cortex by enhancing the biological electromagnetic energy of the human body and collaterals, and thus promote the metabolism, hypnotic, analgesic, sedative, and blood activating of the bone and joint tissue. And eliminate the effect of anxiety. At present, it is commonly used to treat insomnia, neurasthenia, cervical spondylosis, peri arthritis of the shoulder, and other chronic diseases of bone and joint, as well as the pain and numbness caused by these diseases.
The application range of NdFeB magnets is as follows:
The field of Electroacoustics: loudspeaker, receiver, microphone, alarm, stage audio, car audio, and so on.
Electronic and electrical appliances: permanent magnet mechanism vacuum circuit breaker, magnetic latching relay, watt-hour meter, water meter, sound meter, reed pipe, sensor, etc.
Electrical field: VCM, CDDVD ROM, generator, motor, servo motor, micro motor, vibration motor, and so on.
Machinery and equipment: magnetic separation, magnetic separator, magnetic suspension, magnetic machinery, and so on.
Healthcare: MRI, medical devices, magnetic therapy health products, magnetized fuel economizer, and so on.
Other industries: magnetization paraffin, pipe descaler, magnetic fixture, automatic mahjong machine, magnetic lock, leather, toy magnetic, tool magnetic, craft gift packaging, etc.
