Intrinsic coercivity of sintered Neodymium magnets increase with decreasing grain size, and grain refining technology is an effective approach to enhance intrinsic coercivity of sintered Neodymium magnets, thus it is treated as a main solution to fabricate high intrinsic coercivity magnets with low/free heavy rare earth elements. Microstructure of grain refined magnets was optimized via improvement of manufacturing process, then its intrinsic magnetic properties can be brought into full play and obtained higher magnetic properties with low rare earth content. Beyond that, grain refining technology is no limit on the dimension which unlike grain boundary diffusion technology.
