Anisotropic Nd-Fe-<i>M</i>-B flakes by single-roller melt spinning

Abstract

Anisotropic Nd13Fe81−xMxB6 flakes (M=0.5–3 at. % one of Ti/Zr/V/Ta/Mo/Zn) are reproducibly obtainable using single-roller melt spinning at lower substrate velocities (Vs, 8–15 m/s). The degree of preferred orientation (DPO) of spun flakes calculated from x-ray diffraction patterns is 70%–97% on the free surface, 50%–80% on the wheel surface, at Vs=8, 10 m/s. In the case of adding 1 at. % of Ti/V/Mo/Zr/Ta, Vs=8 m/s, the resultant DPO value can be higher than 50% across the whole thickness. Magnetic measurements on spun flakes show highly anisotropic behavior. Maximum energy product of Nd13Fe80ZrB6 flakes spun at 12 m/s, pulse magnetized to 5.5 T, and measured normal or parallel to the flake surface is 144 kJ/m3 (18 MGOe) or 124 kJ/m3 (15.5 MGOe), respectively.