Nd_(8.5)Fe_(84)Nb_(0.5)Zr_(0.5)B_6Cu_(0.5)稀土永磁合金磁性能的研究

Study on the Magnetic Properties of the Rare Earth Permanent Magnet Materials of Nd_(8.5)Fe_(84)Nb_(0.5)Zr_(0.5)B_6Cu_(0.5)

采用熔体快淬法制备出了不同快淬速度(铜轮转速)的Nd8.5Fe84Nb0.5Zr0.5B6Cu0.5稀土永磁合金条带,研究了制备工艺和晶化工艺对该合金磁性能的影响.研究结果表明:快淬速度对该合金的磁性能有很大的影响,合金在20 m/s快淬时磁性能最佳;晶化温度过高或者晶化时间过长,都会造成晶粒尺寸过大,其比表面积减小;晶化温度过低或者晶化时间过短,晶化不完全,造成软、硬磁性相析出较少和大量非晶相的存在,都阻碍软、硬磁性之间的交换耦合作用,影响合金磁性能的提高.经最佳晶化工艺处理后合金在20 m/s快淬时具有最佳磁性能,即剩余磁饱和强度Br=0.72 T、矫顽力Hc=380.98 k A/m和最大磁能积(BH)max=103.72 k J/m3.

With the aim at exploiting the magnetic properties of the rare earth permanent magnetic alloy of Nd8.5 FeB4 Nb0.5Zr0.5 B6Cu0.5, we prepared ribbons deliberately at different quenching rates and then particularly investigated the effect of quenching rates and annealing technique for crystallization on the magnetic properties of the alloy. The result shows that rapid quenching rate has great effect on the magnetic properties of the alloy. The optimum magnetic properties of the alloy are obtained at the rapid quenching rate of 20 m/s. When the crystallization temperature is too high or the time too long, the grain of crystallization phase becomes oversized and the specific surface area of the grain is reduced. When the crystallization temperature is too low or the time too short, the crystallization process is incomplete, which leads to the less precipitation of soft phase and hard phase and much residue of amorphous phase, and thus exchanging coupling between soft phase and hard phase is impeded, deteriorating the improvement of magnetic properties of the alloy. The alloy prepared at the quenching rate of 20 m/s and treated by adequate crystallization technique exhibits the optimum magnetic properties, which are remanent magnetism Br = 0.72 T, coercive force He = 380.98 kA/m and maximum magnetic energy product （BH）max = 103.72 kJ/m3, respectively.