| Nano-composite permanent magnet is a new type of rare-earth permanent magnetic material developed recently.This magnet consists of magnetically hard-phase and magnetically soft phase coupling in nanometer and posses the potential for high coercive force and high remanence as well as excellent magnetic properties.Up to now,many ways such as melt spun,mechanical alIoying(MA) and hydrogenation disproportionation desorption recombination(HDDR),powder metallurgy,Reduction and diffusion was used to obtain the magnets,whereas the magnetic properties can not reach the theoretically predicaion calculation.Microstructure,crystal grain size as well as degree of magnetically hard-phase and magnetically soft phase coupling had an immediate effect on magnetic properties.Sm2Fe17N3/Fe3Pt is produced by melt-spinning and in-situ nitrogen technics.The structure and magnetic properties are analyzed by means of X-ray Diffaaction,TEM,SEM and TG-DTA etc.The result of experiment indicates that,Sm10Fe86.3Pt3.7,Sm9.2Fe84.8Pt6,Sm8.1Fe83.8Pt8.1 melt-spun alloys include inα-Fe,Pt5Sm and Sm2Fe17 and Sm12.8Fe68.6Pt6 melt-spun alloy include in Sm2Fe17,α-Fe,Pt5Sm and Fe3Pt.The SmFePt nitride includes inα-Fe,Sm2Fe17N3 and Fe3Pt.Pt5Sm will break down during nitriding.Pt andα-Fe compound Fe3Pt whenα-Fe was separates from Sm2Fe17 alloy.We have produced successfully exchange coupled Sm2Fe17N3/Fe3Pt nanocomposite material.The microstructure doesn`t accord with ideal model of exchange coupled magnet material,So Sm2Fe17N3/Fe3Pt nanocomposite material has low Hci,Ms and Mr.In addition,the volatilization of element Sm result in a mass ofα-Fe. |
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