Bonded NdFeB is actually molded by injection or calendering, while sintered NdFeB magnets are pumped and then heated to high temperatures.
Bonded NdFeB magnets contain binder because they are molded by injection or calendering. The density is usually only 80% of the theoretical density. And sintered NdFeB magnet through a complex process of high temperature heating. Therefore, on energy, bonded NdFeB is about 30% lower than sintered NdFeB.
Sintered NdFeB is an anisotropic magnet produced by powder sintering.
After sintering, the blank is produced and then machined (such as wire cutting, slicing, grinding, etc.) into various shapes.
Sintered NdFeB is a hard brittle material that is difficult to process. It has high loss, high cost, poor dimensional accuracy and poor corrosion resistance. The surface needs electroplating treatment.
However, it has the advantage of high performance. Currently, it has achieved more than 50MGOe.
The energy of Bonded NdFeB magnet is only about 5% of sintered NdFeB. At present, the magnetic energy of sintered ndfeb magnet can reach more than 50MGOe, while the binding magnet is generally less than 10MGOe, the highest energy of Flexible NdFeB is only 12MGOe. The performance of the magnetic powder used for bonded NdFeB is generally 15MGOe, and only 10.5MGOe at most after it is made into a bonded magnet. Therefore, sintered NdFeB generally has a wider range applications than bonded NdFeB.