利用氮化铝掺杂对热变形钕铁硼磁体电阻率及磁性能的研究

Study on Resistivity and Magnetic Properties of Hot Deformed NdFeB Magnets by Aluminum Nitride Doping

为加快高速永磁电机的发展,提高钕铁硼电阻率,提高永磁电机转子钕铁硼永磁体的服役稳定性及延长其使用寿命就至关重要。采用高电阻率AlN掺杂来提高热变形钕铁硼磁体的电阻率。将AlN与NdFeB快淬粉混合均匀后,采用热压热变形成型方法制备了不同质量分数AlN掺杂NdFeB磁体,研究了AlN掺杂对热压热变形NdFeB磁体的热压致密性、电阻率及磁性能的影响。结果表明,随AlN质量分数的提高,热压磁体的密度逐渐降低,热变形磁体的电阻率逐渐增大,但是磁性能呈线性下降的趋势。当AlN质量分数为1%时,磁性能下降明显,剩磁为1.175T,矫顽力为511.7 kA/m,最大磁能积为196.0 kJ/m~3,磁性能整体下降50%,损耗明显。其电阻率为257μΩ·cm,比未掺杂热变形NdFeB磁体(230μΩ·cm)的高11.7%。

In order to accelerate the development of high-speed permanent magnet motor and improve the resistivity of NdFeB,it is very important to improve the service stability and prolong the service life of permanent magnet rotor NdFeB permanent magnet.The high resistivity AlN doping was used to improve the resistivity of thermally deformed NdFeB magnets.After mixing AlN and NdFeB fast quenching powder evenly,NdFeB magnets with different mass fractions of AlN were prepared by hot pressing and hot deformation molding method.The effects of AlN doping on the hot pressing compactness,resistivity and magnetic properties of hot pressing and hot deformation NdFeB magnets were studied.The results show that with the increase of the mass fraction of AlN,the density of the hot-pressed magnet decreases gradually,and the resistivity of the heat-deformed magnet increases gradually,but the magnetic properties of the hot-deformed magnet decrease linearly.When the mass fraction of AlN is 1%,the magnetic energy decreases obviously,the remanence is 1.175 T,the coercivity is 511.7 kA/m,the maximum magnetic energy product is 196.0 kJ/m~3,the magnetic energy decreases by about 50%,and the loss is obvious.The resistivity is 257μΩ·cm,which is 11.7%higher than that of without doping thermal deformation NdFeB magnets(230μΩ·cm)