Research progress and prospects of Ce-containing NdFeB permanent magnets

Abstract

NdFeB magnets are permanent magnetic materials based on the intermetallic compound Nd₂Fe₁₄B, which are widely used due to their excellent magnetic properties. With the rapid advancement of the NdFeB magnet industry, the consumption of crucial rare earth elements such as Pr, Nd, Dy, and Tb has significantly increased, resulting in escalating raw material prices. Conversely, the element Ce accumulates in large quantities and remains underutilized. To mitigate the production costs associated with NdFeB magnets and promote a more balanced utilization of rare earth resources, considerable attention has been directed towards Ce-containing NdFeB ((Ce,Nd)-Fe-B) magnets in recent years. This review article summarizes the research progress on (Ce, Nd)-Fe-B magnets. Firstly, the distinctions in phase composition and intrinsic properties between CeFeB and NdFeB magnets are presented, and the coercivity mechanisms of (Ce, Nd)-Fe-B magnets are then explored. Subsequently, the influences of factors such as Ce content, addition of metallic elements, and heat treatment on the magnetic properties and microstructure of rapidly-quenched and sintered (Ce, Nd)-Fe-B magnets are discussed. Meanwhile, the grain boundary diffusion processes of (Ce, Nd)-Fe-B magnets are scrutinized. Finally, the challenges faced by (Ce, Nd)-Fe-B magnets and the corresponding solutions are proposed, and the prospects and further developments in this exciting field of (Ce,Nd)-Fe-B magnets are also suggested.