Development Trend of High Performance Hot-deformed Nd-Fe-B Magnet

摘要

Nd-Fe-B based permanent magnets are widely used for various applications due to their excellent magnetic properties. However, the increasing demand for Nd-Fe-B based permanent magnet with growth of the eco-friendly vehicle market is accelerating the imbalance between the supply and demand of rare-earth elements such as Dy, Tb, and Nd. For heavy rare earth (HRE)-free or Nd-lean magnets, it is necessary to refine the crystal grains to the single domain size of Nd_2Fei_4B phase (~300 nm), and to form the uniform and continuous grain boundaries phase as a non-magnetic phase. The hot-deformed Nd-Fe-B magnet have a very high potential as a HRE-free or Nd-reduced permanent magnet due to its ultra-fine grain size of ~300 nm. In this paper, we introduce overall research and development trend for the hot-deformation process of Nd-Fe-B based permanent magnets to develop the high performance HRE-free or Nd-lean permanent magnets.