Research status and prospect of high abundant rare earth of permanent magnetic materials

The criticalrare earth (RE) elements (Pr, Nd, Dy, Tb)have been overusedwith the expanding application areas and surging demand of RE permanent magnetic materials.High abundant rare earth (HARE) elements such as La, Ce, Y, however, are constantly overstocked.They can not only reduce costs, but also be used to achieve a comprehensive balancedutilization of rare earth resources. It is imperative, important and necessary to do research and develop the cost-effective HARE permanent magnetic materials for national strategic security and the reduction of the costs of raw materials. The higher value utilization of these magnetic materials has been extensively studied by a large number of scholars in various groups. The systematic studies focus on the thermal stability of the main phase, the type of the second phase, the phase precipitation behavior, the valence state and metallurgical behavior of trace elements sinceall of these parameters are quite different from those of the widely used Nd-based commercial magnets. This paper has reviewed the recent progress of their phase structures, magnetic properties, microstructuresand corrosion resistance of the magnetic materials and shed light on their research and development.