| The series of Sm-Fe-N nanocrystalline composite magnets has excellent intrinsic magnetic properties. Because of their high magnetic energy product of 1090kJ/m3 together with low rare earth concentration and high chemical stability, they are believed to be promising new candidates for applications in inexpensive bonded permanent magnets.In this thesis ,the Sm3(Fe, M)29Nx/a-Fe (M=Co , V, Mn) nanocomposite permanent magnetic materials with high performance have been obtained by crystallizing over-quenched ribbons. The effects of Fe content, the additions of Co, V and Mn on the microstructure of Sm-Fe alloys and magnetic properties of the ribbons with different composition are systematically studied.X -ray diffraction, scanning electronic microscope, transmission electronic microscope and vibrating-sample magnetometer were used to analysis the processing parameters of melt spun and crystallization treatment, microstructure and magnetic properties. The result of experiment indicated that: As the saturated vapor tension is lower than that of Fe, Sm volatilized firstly which is propitious to form Sm-Fe phase. In the later crystallization process, the magnetic property of Sm-Fe alloys verify as the time and temperature of crystallization are changed. The condition of nitrogenation has a more notable effect on the magnetic property. If the time of nitrogenation is long enough, there are SmN and α-Fe phase in specimen of alloys. If the time of nitrogenation is too short, there is Sm-Fe phase of un-nitrogenation, the concentration of nitrogen is not of uniformity, and the concentration of nitrogen is far too low, all of above can result in decreasing of magnetic property. In order to obtain excellent magnetic property, our conclusion is that : When nitrogenation at 480 ℃,the optimal nitrogenation time is 6 hours.Besides, long-term ball milling deteriorated the magnetic properties. The reason is the oxidation of the power.
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