Misch metal-Fe-B melt spun magnets with 8 MGOe energy product

The magnetic and structural properties of melt spun MM-Fe-B ribbons, where MM stands for misch metal, were examined. It has been shown that the MM16Fe75B9ribbon can exhibit a coercive force of 9.4 kOe and an energy product of 8.1 MGOe when it was quenched at the optimum rate of 20 m/sec, in terms of quenching wheel surface velocity. Microstructural and X-ray analysis revealed that the optimum-quenched ribbons consist of grains with size from less than 10 nm to 300 nm, and have c-axis orientation in the free surface. The plastic magnets made of the optimum-quenched ribbons have been shown to exhibit a coercive force of 7.6 kOe and an energy product of 4.4 MGOe, which compare favorably to anisotropic ferrite magnets.