机械合金化方法制备的Nd(Fe,V,Ti)_(12)N_y磁体的结构与磁性

Structure and Magnetic Properties of Nd(Fe,V,Ti)_(12),N_y Alloys Prepared by Mechanical Alloying

采用Ｘ射线和磁性测量研究了退火机械合金化ＮｄＦｅ_（１０．５＋０．５ｘ）Ｖ_（１．５（１－ｘ））Ｔｉ_ｘ合金相的形成和磁学性能．根据Ｘ射线和初始交流磁化的结果作出了ＴｈＭｎ_(１２)结构１－１２相的形成与钛的含量，退火温度的关系图．随钛含量增高，１－１２相的形成温度升高，当钛含量ｘ＝１时，１－１２相要在９５０℃以上温度退火才能形成．氮化后，１－１２相的结构不变，居里温度提高的１５０～１８０℃，随钛含量增加氮化物的稳定变差．由于１－１２相的形成温度随钛含量增加而升高，获得纳米尺度的１－１２相变得困难，同时较高钛含量的氮化物·的稳定性较差，结果导致ＮｄＦｅ_（１０．５＋０．５ｘ）Ｖ_（１．５（１－ｘ））Ｔｉ_ｘＮ_ｙ_磁体的矫顽力随钛含量增加明显下降．

Phase formation in annealed mechanical alloying NdFe_(10.5+0.5x)V_(1.5(1-x)) alloys, and magnetic properties of the consequent phases and their nitrides were investigated by using x-ray diffraction. and magnetic measurement. From the x-ray diffractin patterns and ac initial susceptibility we have constructed a phase formation diagram as a function of Ti content x and annealing temperature. The temperature of l-12 phase formation increases with increasing Ti content. When x= I the ThMn_(12) structure l-12 phase is obtained by annealing the as-milled powder at the temperature is enhanced from 150 to 180 . The nitride with low Ti content is more stable than that with high Ti content. Since the increase of temperature of l-12 phase formation makes it more difficult to obtain nanometer sized grain of l-12 phase and the nitride is more unstable with increasing Ti content, the hard magnetic properties of NdFe_(l0.5+0.5x)V_(I.5(1-x))Ti_xN_y, magnets decreases with increasing Ti content.