What is a neodymium magnet? ------Tujin

Neodymium magnet, full name NdFeB magnet, is a rare earth permanent magnet material with neodymium (Nd), iron (Fe), and boron (B) as the main components. It was born in the 1980s and is one of the permanent magnet materials with the strongest magnetic properties known to date. The wide application of neodymium magnets in industry and life makes it an important magnetic material to promote the progress of modern science and technology.

Material composition and manufacturing process
The main components of neodymium magnets are neodymium, iron and boron, which are prepared by powder metallurgy. The specific steps include: melting neodymium, iron, boron and other alloy elements in proportion, rapidly cooling them into powder, then sintering them at high temperature, and then heat treating and machining them to finally make magnets of various specifications and shapes. In order to improve the performance and high temperature resistance of magnets, a small amount of rare earth elements such as dysprosium, lanthanum, and samarium are usually added. These elements can enhance the coercive force and temperature stability of magnets.

Magnetic properties
The magnetic properties of neodymium magnets are extremely excellent, mainly reflected in the following aspects:

High magnetic energy product
The maximum magnetic energy product of neodymium magnets is generally between 30 and 50 mega-gauss-oersteds (MGOe), far exceeding traditional ferrite magnets (generally below 3.5 MGOe) and samarium cobalt magnets (about 20-30 MGOe). Neodymium magnets can generate very strong magnetic fields in a small volume, which makes neodymium magnets particularly outstanding in applications that require high-intensity magnetic fields.

High remanence
Neodymium magnets have a high remanence value, maintain magnetism for a long time, and can continuously exert strong magnetic force.

Strong coercive force
Neodymium magnets have a strong ability to resist external magnetic field interference, are not easily demagnetized, and ensure stable magnetism.

Diversity of specifications and shapes
Neodymium magnets can be manufactured in a variety of different shapes and sizes, including round, square, ring, bar and various special-shaped structures to meet the needs of different customers and applications. Whether it is a small electronic component magnet or a large motor magnet, it can be customized according to the design requirements.

High temperature resistance
Although neodymium magnets have strong magnetism, their operating temperature is limited. The maximum temperature applicable to standard neodymium magnets is generally around 80°C, and the magnetic properties will begin to decay above this temperature. In order to adapt to higher temperature environments, neodymium magnet manufacturers will use high-temperature neodymium magnet formulas, add elements such as dysprosium (Dy), and increase its maximum operating temperature to 150°C or even higher, thereby meeting the needs of high-temperature occasions such as new energy vehicle motors and industrial equipment.

Anti-corrosion and surface treatment
The material of neodymium magnets itself is susceptible to moisture and oxygen in the air, resulting in surface oxidation and rust, which in turn affects magnetism and appearance. Therefore, neodymium magnets must be subjected to surface protection treatment, which is commonly nickel-plated, zinc-plated, copper-plated, gold-plated, and coated with three-proof paint. These treatments not only effectively prevent oxidation, but also enhance the wear and corrosion resistance of the magnets and extend their service life.

Application fields
Due to its super strong magnetic properties, neodymium magnets are widely used in many industries:

Electronic products
Mobile phone speakers, headphones, computer hard drives, optical drives, magnetic cards, etc. all rely on neodymium magnets to provide strong and stable magnetic support.

Motors and generators
Especially in the fields of new energy vehicle motors, wind turbines, household appliance motors, etc., neodymium magnets have achieved miniaturization and high efficiency.

Magnetic separation equipment
Used for metal impurity separation and ore separation in industrial production.

Medical equipment
In magnetic resonance imaging (MRI) instruments, neodymium magnets provide a strong and stable magnetic field.

Sensors and automation instruments
As an important component of sensor elements, neodymium magnets are used in various detection and measurement equipment.

Toys and magnetic fixtures
Neodymium magnets are also widely used in daily necessities such as magnetic toys, magnetic door buckles, and magnetic hooks.

Precautions for use
Neodymium magnets are very hard, but they are also very brittle and are easy to break or shatter when they collide or fall. Therefore, be careful when using and carrying them to avoid violent collisions. In addition, although neodymium magnets have strong anti-demagnetization ability, they should still be avoided from strong external magnetic field shocks. They should be stored away from electronic devices and magnetic cards to avoid adverse effects.