The effect of element doping and heat treatment on the impact resistance of Nd-Fe-B sintered magnets

Abstract

The effects of rare-earth contents, substitutions, and heat treatment parameters on the impact resistance of the Nd-Fe-B sintered magnets were investigated. Analysis shows that the impact resistance increases linearly with increasing plastic rare-earth-rich phase in the investigated magnets. Heavy rare-earth Dy substitutions for Nd help us to improve the impact resistance. The bending strength and impact resistance during annealing process was investigated. It is found that the annealing process affects the bending strength and impact resistance remarkably. Both the bending strength and the intrinsic coercivity are poor in the as-sintered specimen. In the postsintering annealing process, both of them get improved and the change of intrinsic coercivity is similar to that of the bending strength. Study showed that the optimized heat treatment parameters help us to improve the bending strength and impact resistance of the sintered Nd-Fe-B magnets. Study shows that the sintered Nd-Fe-B magnets with improved impact resistance can be produced by the adjustment of compositions and heat treatment parameters. © 2008 American Institute of Physics.