机械化学法制备高性能SrFe12O19永磁材料

Influence of Nano-sized Raw Materials on Magnetic Properties of SrFe_(12)O_(19)Materials

以纳米级碳酸锶和氧化铁粉为原料,采用机械化学法制备了SrFe12O19预烧粉后烧制成磁性块体材料。分别在950、1000、1050和1100℃4个烧结温度下制备了样品,对比了1100℃下烧结的商用样品,分析了材料的微观结构变化。研究了材料的断裂韧性、剩磁、矫顽力、内禀矫顽力以及最大磁能积等参数的变化,以说明不同温度下材料的力学性能与磁性能的变化趋势。结果表明,在相同工艺下,采用纳米原料粉制备的材料,其力学性能与磁性能比商用样品有大幅度提高。不同温度下材料性能变化的原因在于烧结过程导致的微观结构变化所致。

SrFe12O19 materials were synthesized through mechanochemical method by using nano-sized Fe2O3 and SrCO3 as the raw materials during the preparation of presintered powders. Four samples were produced at the sintering temperature of 950℃, 1 O00℃, 1 050℃ and 1 100℃. The difference among the microstructure of the samples is analyzed, and comparison is made with respect to the commercial product produced at the sintering temperature of 1 100℃. The changes of magnetic properties of these samples are shown by the parameters of the remnant magnetism, coercive force, intrinsic coercive force, and the mechanical properties are represented by the fracture toughness. It is shown that the fracture toughness and magnetic properties of the samples, produced from nano-size raw powders, are better than those of the commercial product. The better performance of materials may be due to the microstructure of materials.