Due to the high magnetic performance, Nd-Fe-B sintered magnets have a large share even after encountering the rare earths resource issue in 2010. In these last few years, rare earth magnet manufacturers have focused on saving heavy rare earths (HREs) apart from improvement of magnetic properties. There are three ways to enhance coercivity with less HREs or without HREs: grain size refinement, the Grain Boundary Diffusion process, and modification of the grain boundary phase.
The demand for high performance magnets is expected to increase and we welcome alternative magnets containing less or no rare earths. Requirements for such new magnets would be a heat resistance up to around 150 degree C, and higher ratio of remanence to the cost in comparison with the Nd-Fe-B magnets.