Mg纳米粉对钕铁硼磁性和热稳定性的影响

为了提高烧结NdFeB磁体的磁性能和热稳定性,采用二元合金法添加Mg纳米粉制备了NdFeB材料.利用扫描电子显微镜、X射线衍射仪和永磁特性测试仪对烧结NdFeB磁体的微观结构、磁性能和热稳定性进行了分析.结果表明,随着Mg纳米粉含量的增加,NdFeB磁体的矫顽力、剩磁和最大磁能积逐渐升高.当添加的Mg纳米粉的质量分数为0.1%时,NdFeB磁体的磁性能达到最优.添加质量分数为0.1%的Mg纳米粉后,NdFeB磁体的剩磁具有最大值.当温度处于100~150℃范围内时,矫顽力的温度系数降低,因而矫顽力的热损失幅度减小.

Effect of Mg nanopowder on magnetic properties and thermal stability of NdFeB

In order to improve the magnetic properties and thermal stability of sintered NdFeB magnets, the NdFeB materials were prepared through adding the Mg nanopowder with the double-alloy method. The microstructure, magnetic properties and thermal stability of sintered NdFeB magnets were analyzed with the scanning electron microscope(SEM), X ray diffractometer(XRD)and permanent magnetic feature tester. The results show that with increasing the content of Mg nanopowder, the coercivity, remanence and maximum magnetic energy product of NdFeB magnets gradually increase. When the mass fraction of added Mg nanopowder is 0.1%, the magnetic properties of NdFeB magnets are optimum. After adding the Mg nanopowder with the mass fraction of 0.1%, the NdFeB magnets have the maximun remanence. When the temperature is in the range from 100 ℃ to 150 ℃, the temperature coefficient of coercivity reduces, and thus the heat loss amplitude of coercivity decreases.