Phase Formation and Magnetic Properties of La‐ and Ce‐Substituted (Nd_1−2xRE_xPr_x)_2.28Fe_13.58B_1.14 Melt‐Spun Ribbons

Abstract

Nd-Fe-B permanent magnets have been widely used in many industries such as medical equipment, electronic information, energy transportation, and the automobile industry. [1][2][3][4] With the continuous development of new energy vehicles, robots, and other high-tech industries, the demand for highperformance Nd-Fe-B magnets is constantly increasing, which leads to the overuse of low-abundant rare-earth (RE) metals such as Nd, Dy, and Tb. It has become urgent and important to find alternatives for these key metals. Highly abundant RE metals such as La, Ce, and Y have not been effectively utilized in the production of Nd-Fe-B magnets. Therefore, partially replacing Nd with highly abundant RE metals would be a promising way to explore the sustainable development of comprehensive utilization of RE metals. However, magnetic properties of Nd-Fe-B magnets with La and Ce have deteriorated unavoidably through the traditional fabrication technology because intrinsic magnetic properties of La 2 Fe 14 B and Ce 2 Fe 14 B phases are inferior to those of Nd 2 Fe 14 B, Dy 2 Fe 14 B, and Tb 2 Fe 14 B phases. [5] To improve the magnetic properties of Nd-Fe-B magnets with La, Ce, and Y substitution, it is essential to modify the composition, control phase constitution, and microstructure and design of the novel fabrication technologies for the production of Nd-Fe-B magnets. Recently, the magnetic performances of Ce-and La-substituted Nd-Fe-B alloys were investigated. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] Lei et al., [6] Zhang et al. [7] and Rehman et al. [8,9] studied the phase composition, microstructure, and magnetic properties of Nd-Fe-B and Ce-Fe-B melt-spun ribbons with different doping metals such as La, Ta, and Ge. Zhu et al. [10] reported that (Nd 1Àx Ce x ) 30 Fe bal B magnets prepared by the double main-phase alloy method show good magnetic properties. The maximum magnetic energy product ((BH) max ) of the magnet with 30% Ce content of total RE metals is 43 MGOe. According to the experimental results, [6][7][8][9][10] the effect of alloy composition, microstructure, and processing conditions on magnetic properties of Nd-Fe-B alloys with La and Ce substitution is significant. In our previous work, Ce-Y-cosubstituted Nd-Fe-B melt-spun ribbons show good magnetic properties. [12] The high abundance of the RE metal La has the potential to replace Nd in Nd-Fe-B magnets to produce high-performance magnets. However, there are a few reports on the effect of La, Ce, and Pr cosubstitutions on phase formation and the magnetic properties of Nd-Fe-B melt-spun ribbons. It is necessary to further understand the relationship between phase formation, phase structure, and magnetic properties of Nd-Fe-B alloys with Ce-Pr and La-Pr cosubstitutions, which will provide reference for the development of new fabrication technologies and high-