Progress and Prospects of SmFeN Magnets

Abstract

More than 20 years have passed since SmFeN was discovered. At that time, because of its huge anisotropy field and high Curie temperature, SmFeN was expected to become a next generation permanent magnetic material. However, SmFeN has the drawback that it cannot be sintered. Although considerable research has been carried out, this problem has still not been overcome. Therefore, SmFeN magnets have less potential for mass commercialization than NdFeB magnets. We propose two methods that are expected to lead to the commercial use of SmFeN. One is to increase coercivity by controlling the shape of particles, consequently increasing heat resistance. The other is to form products with new magnetic patterns by examining the magnetic orientation process. Moreover, it is important to use all rare earth elements efficiently. Thus, we consider that SmFeN should be reappraised as a magnetic material.

Additive Manufacturing of Rare Earth Permanent Magnetic Materials: Research Status and Prospects

“…Compared with traditional processing methods, it is suitable for a small number of diverse and personalized designs due to its higher efficiency, lower energy consumption, and higher utilization rate of materials [31][32][33][34][35]. Fim R et al [30,34,[36][37][38][39][40][41][42][43] explored the freedom of shape of rare earth permanent magnets by AM technology and successfully prepared magnets with complex geometric structures, as shown in Figure 1. A magnetic gearbox with a helical teeth profile prepared by AM technology is shown in Figure 1b.…”

Novel Powder Processing Technologies for Production of Rare-earth Permanent Magnets

“…Fig. 6 Dependencies of coercivity on particle size for Sm 2 Fe 17 N 3 fine powders prepared by the mechanical pulverization and reduction diffusion methods 11,[41][42][43] .…”

Novel powder processing technologies for production of rare-earth permanent magnets

“…The inset shows a cross-sectional TEM image of a Zn-coated powder[40]. Dependencies of coercivity on particle size for Sm 2 Fe 17 N 3 fine powders prepared by the mechanical pulverization and reduction diffusion methods[15,[45][46][47].…”