Magnetic texture of Nd2Fe14B solidified in the surface layer of anisotropic sintered-magnets

The arrangements of the easy magnetization axis [001] of columnar Nd2Fe14B crystals in the laser scanned layer on anisotropic sintered Nd15Fe77B8 magnets were investigated by XRD and the Bitter method. The results show that the common effects of both the heat flux and the substrate magnetization orientation constrain the columnar Nd2Fe14B solidified from the laser melting pool to form the c-axis texture orientated with the same direction as that of the substrate, when the geometric relationship between the heat flux in the laser scanning layer and c-axis texture orientation of the substrate is perpendicular to each other, and if the laser scanning velocity is no less than 25 mm·min−1. The c-axes of columnar Nd2Fe14B crystals are no longer randomly distributed in the plane normal to their preferential growing direction as they are randomly done in both ingots cooled by water-cooling copper mould and directionally solidified Nd-Fe-B rods.