Document Type : Review Article
1 MSc graduate in materials science and engineering, Iran university of science and technology (IUST)
2 R&D Department, Mapna Generator Engineering and Manufacturing Company (PARS)
Permanent Magnets (PMs) are employed in many modern devices, thanks to their unique properties. Electrical machines, i.e., motors and generators, are a major application of PMs, which produce the required magnetic field. When there are severe constraints on the weight and dimensions of the device (e.g. in hybrid electric vehicles or wind turbines), using high-energy PMs would be of crucial importance. Currently, PMs which contain Rare-Earth Elements (REEs), e.g. Sm-Co and Nd-Fe-B, are the most commonly used and the most powerful practical PMs. However, the monopolized supply of the raw materials required for the production of these PMs as well as the recent rise in their global price, have encouraged researchers to investigate some methods for reducing the consumption of REEs or substituting other PMs for those with REEs. This paper studies the state of the art advances in developing PMs with less or no REEs and the corresponding achievements.