Microstructure and magnetic properties of sintered NdFeB magnets with improved impact toughness

Abstract

An effort to increase the impact toughness of Nd–Fe–B sintered magnets by adding small amounts of Al, Nd, Ga, Cu, and Nb was successful. No significant compromise to magnetic properties occurred. Based on this work, a series of sintered Nd–Fe–B magnets with improved toughness was developed, which we call ToughNEO™. Small precipitates, which may contribute to the improvement of toughness, were observed using scanning electron microscope for all samples with improved toughness. Tumbling and drilling tests further verified the improved toughness of these developed ToughNEO™ magnets.