High cerium content (Nd-Pr-Ce)2Fe14B melt-spun ribbons with high coercivity

Abstract

The effects of wheel speeds on the magnetic properties and microstructures of [(Nd,Pr)1–xCex]-Fe-B melt-spun ribbons were investigated. Compared to melt-spun ribbons with low cerium (Ce) content (x = 0.2), amorphous formation can be suppressed at high wheel speed in the ribbons with a relatively high Ce content (x = 0.8), and with the increase of the wheel speed, the magnetic properties of the ribbons with high Ce content raise continuously. At high wheel speed, the coercivity mechanism of melt-spun ribbons is mainly pinning field, and the high wheel speed introduces a large number of defects into the matrix as pinning sites. Furthermore, ribbons with high Ce content form a fine and uniform grain structure, so the grain boundary area enlarges, which further hinders the movement of domain walls. The combined effects of the above factors enable ribbons with high Ce content to have excellent magnetic properties (Hcj = 0.977 T, Mr = 64 m2 A/kg) at the wheel speed of 35 m/s.