High performance NdFeB permanent magnetic material prepared by spark plasma sintering

A new type of NdFeB magnet with high magnetic properties was prepared by spark plasma sintering(SPS) method.The effect of sintering and heat treatment techniques on microstructures and magnetic properties of magnets was systematically studied.The microstructures and magnetic properties of magnet materials were tested by scanning electronic microscope(SEM) and B-H loop-line instrument,respectively.The results show that the densification of magnets is greatly improved with the increase of sintering temperature,while exorbitant sintering temperature will decrease the density of magnets because the Nd-rich phase distributes poorly along the boundaries of the NdFeB grains.Under optimum processing conditions,the SPS NdFeB magnet possesses the best magnetic properties with remanence of 1.351T,coercive force of 674.4kA/m and maximum energy product of 360.4kJ/m~3.