Specific questions about permanent magnet production

[trini]

I would like to know if anyone here has ever been involved in permanent magnet production, and more specifically, with the sintering process. What temperature must a NdFeB magnet be heated to for sintering and also, how do you determine the length of time you sinter for? What kind of density increases are typically observed post sintering?

Also before the sintering stage, after the material has been compressed, is it safe to handle the compressed ore without it crumbling apart, or must the compressed shape be kept in the die for the sintering process?

 

[Navin A S]

The sintering temperature of a NdFeB magnet is typically around 900°C (1650°F). Depending on the material, the sintering time can range from 5 to 30 minutes. The density increase due to sintering is typically between 5-15%. After compression, the magnet should remain in the die for sintering. However, it is possible to remove the magnet from the die and handle it, if the magnet is kept cool and not exposed to high temperatures. It is also important to keep in mind that the magnet may be more fragile during this stage, so it is important to handle it with care.

 

[oswaler]

As a scientist with experience in permanent magnet production, I can provide some insight into your questions about the sintering process. The sintering process is a crucial step in the production of permanent magnets, as it helps to improve the magnetic properties and increase the density of the material.

To answer your first question, the temperature required for sintering a NdFeB magnet typically ranges from 1000-1200°C, depending on the composition and desired properties of the magnet. This temperature is necessary to melt the binder material and fuse the particles together, creating a solid and dense structure.

The length of time for sintering also varies depending on the specific magnet being produced and the sintering temperature. Generally, sintering can take anywhere from 1-4 hours, with some magnets requiring longer sintering times for optimal properties.

In terms of density increases, it is common to see a 5-10% increase post-sintering. This increase is a result of the particles fusing together and eliminating voids within the material.

As for handling the compressed ore before sintering, it is generally safe to handle as long as the material is compacted enough to maintain its shape. However, it is important to handle it carefully to avoid any potential damage or loss of material.

I hope this information helps to answer your questions about permanent magnet production and the sintering process. As with any scientific process, it is important to carefully control and monitor the sintering parameters to ensure the production of high-quality magnets.