Permanent magnet material, also known as hard magnet material, material that is difficult to magnetize and difficult to demagnetize once magnetized, its main characteristic is to have high coercivity, it’s the most important category of the magnetic materials. Next, we’ll start with the permanent magnetic materials and gradually explore the world of magnetic materials.

Rare earth permanent magnetic material is one of the most important magnetic products, since it’s appearance in the 1960s’, three generations of products have been mass produced and applied, the fourth generation of rare earth ferronitrogen permanent magnetic products is in the reserch and development stage and may become a new generation of rare earth permanent magnetic products in the future.
The first and second generation of SmCo were prepared by powder metallurgic, the main raw materials are samarium and cobalt, which are expensive and belong to strategic resources. Therefore, the mass production and large-scale use of SmCo are limited and are not widely used. Mainly used in aviation, aerospace and defense industry.
The success of the third generation NdFeB rare earth permanent magnet is of great significance, it not only has amazing excellent performance and record high magnetic energy product, but also it has replaced expensive strategic cobalt and scarce samarium with cheap,abundant iron and neodymium. The high quality and low price of NdFeb permanent magnet and its huge production potential and wide application prospect have caused a great shock among magnet researchers and manufacturers all over the world. Since the announcement of the existence of NeFeB in 1983 by the Japan’s sasakawa and others, the various performance records of its magnets have been repeated set, and it has become the centre topic of international academic conferences for many times. Through comparison, it can be found that NdFeB is the most cost-effective rare earth permanent magnetic material, and the magnetic property of sintered NdFeB is better than that of bonded NdFeB, but bonded NdFeB has better machining ability.
Comparison of the properties of permanent magnetic materials: