INVESTIGATION OF LOW MELTING-POINT BOUNDARY PHASE IN SINTERED (Ce,Nd)-Fe-B MAGNETS

摘要

A (Ce,Nd)-Fe boundary phase with low melting-point was obtained in the sintered Ce_9Nd_(21)Fe_(bal)B_1 magnets by the two powders blending method. Ce element enriched in the boundary phase and decreased the melting point. The melting-point of the boundary phase decreases with the increase of Ce content. Thus, the high performance magnets with fine grain and low oxygen content can be obtained by low temperature sintering. The sintered Ce_9Nd_(21)Fe_(bal)B_1 magnet with 600 PPM oxygen content and magnetic property of Br = 13.5 kGs, H_(ci) =9.5 kOe and (BH)_(max) =42.8 MGOe has been fabricated by the low melting-point phase formation and low temperature sintering method. Microstructure and chemistry composition of the magnet and the low melting-point boundary phase were investigated by SEM and TEM.