Oxidation and corrosion behaviors of NdFeB Magnet prepared by spark plasma sintering
放电等离子烧结NdFeB磁体的氧化和腐蚀行为

Anisotropic NdFeB magnet was prepared by spark plasma sintering(SPS)technique. Magnet with same composition was produced using conventional sintering method for comparison. The electrochemical properties in electrolytes and reaction kinetics in oxidizing environments of the magnets were studied. The microstructure and compositions of the magnets were observed with scanning electron microscope and energy dispersive X-ray detector. Compared with conventional sintered NdFeB maggnet,the SPS processed magnet has an original microstructure,i.6.the grain size of the Nd_2Fe_(14)B main phase is fine and uniform,and the fine Nd-rich phase does not form along the grain boundaries of main phase,but agglomerates into the triple junctions.Therefore,the pathways for corrosion propagation are restricted and the inter-granular corrosion process is suppressed effectively. As a result. the SPS NdFeB magnet possesses an excellent corrosion resistance.