Permanent Magnets

Manufacturing process

look simple, do complex

Neodymium magnets(NdFeB)

Permanent Magnets

also known as the “neo”magnets made from an alloy of neodymium, iron and boron. It is permanent magnets which is the most widely used, because it offers the highest energy of any other magnetic materials. Neodymium magnets are the strongest type of permanent magnet available commercially, so they have replaced other types of magnets in many applications in modern products, such as brushless DC Motor,magnetic resonance imaging, sensors and magnetic fasteners.

produce process

Permanent Magnets Made-First Step

from raw material to the half-made material, how many processes contains?and what equipment and devices are needed?

1.Burdening: Mix the neodymium powder, iron powder, boron powder and other chemical element in proportion.

2.Melting: Melt the mixture, cooled and solidified into neodymium iron boron alloy ingot or alloy chill plate under vacuum or inert gas in an induction melting furnace.

3.To align the particles, in order to make sure all the magnetic regions are pointing in a prescribed direction.

3.1.HD(Hydrogen Decrepitation): Neodymium iron boron alloy was fused in hydrogen environment.

3.2 Air Mill: The neodymium iron boron powders collide with each other and mixed together, to form a fine magnet powder

ranging from 3 to 5 microns in diameter, in high-pressure air flow. The powder is chemically reactive, capably of igniting

spontaneously in air and therefore must be protected from exposure to oxygen.

3.3.Pressing: Press the magnet powder into the required moulds.

3.4.Isostatic Pressing: Gradually release the equalizing pressure to the compact producing the highest possible energy


4.Sintering: Sinter the neodymium compact, to get low relative density, high mechanical particles contract and high bonding

strength, making the magnet have the microstructure characteristics of high permanent magnetic properties.

5.Tempering: Tempering means that the sintered magnetic particle blank is cooled to a certain temperature and heated again.

The tempering temperature shall be determined by test or thermal difference analysis

Completed semi-magnets have a rough surface and only approximate dimensions. They also exhibit no external magnetic field.

produce process

Permanent Magnets Made-Final Step

1.Machining: Cutting, Milling,Punching, etc.

The permanent magnet material is both brittle and very hard, All of the above processes must be conducted very carefully to minimize chipping and cracking. The usual shape of the neodymium magnet is cylindrical and cubic, while other shapes can be made, but the cost will be higher.It is recommand to discuss with us.

2.Plating: Electronic coating the permanent magnet with Nickel, Zinc, Gold, Epoxy, etc.

Neo magnets, which are prone to rusting or reacting chemically, are almost coated to extend service life.

3.Magnetizing: Produce an external magnetic field to the neo magnets.

Magnetizing machines can not only magnetize the magents, but also small or large magnetic components, to avoid handling and assembling these powerful magnets in their magnetized condition. The high grade magnets, such as EH, AH, require more professtional machines. It is better to contact us with specified techincal data.

4.Packing: Do as required package.

5. Shipping: Send the package.