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用熔体快淬法制备了高性能纳米双相耦合Nd2Fe14B/α Fe磁体,研究了快淬速率和热处理工艺对其磁性能和微结构的影响。实验结果表明,控制快淬速率在12m·s-1时,可直接得到显微组织均匀、α Fe相粒子细小且均匀分布的纳米双相耦合Nd2Fe14B/α Fe磁体。低温退火处理后可消除由少量非晶相带来的成分不均匀性,其最高磁性能为iHc=432.2kA·m-1,Jr=1.08T,(BH)max=115kJ·m-3。快淬速率提高,非晶相体积分数增加,在高温晶化热处理时软硬磁相析出不均匀,个别α Fe相粒子奇异长大,尺寸达到100nm左右,这不利于软硬磁相间的交换耦合作用,有损磁性能。
The high performance nanocomposite Nd2Fe14B / αFe magnet was prepared by melt quenching method. The effects of quenching rate and heat treatment on its magnetic properties and microstructure were studied. The experimental results show that when the quenching rate is controlled at 12m · s-1, the nanocomposite Nd2Fe14B / αFe magnet with uniform microstructure and small and uniform αFe phase particles can be directly obtained. Low temperature annealing can eliminate the compositional heterogeneity caused by a small amount of amorphous phase. The highest magnetic properties are iHc = 432.2kA · m-1, Jr = 1.08T, and (BH) max = 115kJ · m-3. The quenching rate increases and the volume fraction of amorphous phase increases. The hard and soft magnetic phases precipitate unevenly during the heat treatment at high temperature. Some αFe phase particles singularly grow up with the size of about 100 nm, which is not conducive to the exchange coupling between soft and hard magnetic phases Function, detrimental to magnetic properties.