高温稀土永磁Sm(Co_(0.72)Fe_(0.15)Cu_(0.1)Zr_(0.03))_(7.5)的烧结和磁性能研究

Study of Sintering and Magnetic Properties for High Temperature Rare Earth Permanent Magnets Sm(Co_(0.72)Fe_(0.15)Cu_(0.1)Zr_(0.03))_(7.5)

采用粉末冶金法制备高温稀土永磁Sm（Co0.72Fe0．15Cu0.1Zr0．03）7.5，研究了烧结温度对磁体磁性能的影响。结果表明：烧结温度过低，则磁体的致密度较低，难以获得优良的磁性能；烧结温度过高，则Sm挥发，磁体的Sm含量降低，磁性能恶化。磁体的最佳烧结条件为：温度1215℃，保温45min。在上述条件制备的磁体在25℃及500℃时的剩磁夙、内禀矫顽力Hci、最大磁能积（BH）max分别为：0．94T，2276．6kA／m，171．9kJ／m^3及0．67T，509．4kA／m，81.2kJ／m^3；磁体的占．日退磁曲线在500℃时保持为直线，内禀矫顽力温度系数声（25℃-500℃）为-0，16％／℃，最高使用温度达到533℃。

The influence of sintering temperature on magnetic properties of high temperature rare earth permanent magnets Sm（Co0.72Fe0.15CU0.1Zr0.03）7.5 prepared by the conventional powder metallurgy method has been studied. The results show that magnetic properties will be brought down by decreasing densities owing to too low sintering temperature or by vaporization of element Sm owing to too high sintering temperature. The optimum preparation condition was that sintering temperature was 1215℃ and holding time was 45 min. Under the above mentioned condition, the optimum value of Br, Hob, Hoi and （BH）max of the magnet at 25℃ and 500℃ were 0.94 T, 708.4 kA/m, 2276.6 kA/m, 171.9 kJ/m^3 and 0.67 T, 429.8 kA/m, 509.4 kA/m, 81.2 kJ/m^3, respectively. The B-H demagnetization curve maintained at a straight line at 500℃, the intrinsic coercivity coefficient β （25℃-500℃）was -0.16%/℃, and the maximum operating temperature was up to 533 ℃.