制备工艺对(La,Ce)-Fe-B永磁材料CeFe_(2)相含量与磁性能的影响

Effect of preparation process on CeFe_(2) phase content and magnetic properties of(La,Ce)⁃Fe⁃B permanent magnetic materials

分别使用退火和快淬工艺制备了名义成分为(La_(x)Ce_(1-x))_(3.0)Fe_(14)B(x=0,0.05,0.10,0.15,0.20,0.25,0.30,0.35)合金近平衡态和非平衡态试样。采用X射线衍射及热磁曲线分析了La含量对合金中CeFe_(2)相的含量和磁性能的影响。结果表明,合金中CeFe_(2)相的含量随La替代量的增加而单调降低,且非平衡态试样中含有比同等名义成分近平衡态试样更少的CeFe_(2)相,说明制备工艺对CeFe_(2)相的含量影响较大。随La含量的增加,非平衡态试样的饱和磁化强度、剩磁、最大磁能积都有所提高,矫顽力先升高后降低,这是磁晶各向异性场降低与微结构优化的共同作用结果。另外,La不能像其他稀土金属一样进入CeFe_(2)相。

Near⁃equilibrium and non⁃equilibrium specimens with the nominal composition of(La_(x)Ce_(1-x))_(3.0) Fe_(14)B(x=0,0.05,0.10,0.15,0.20,0.25,0.30,0.35)alloy were prepared by annealing and rapid quenching,respectively.The effect of La content on the content of CeFe_(2) phase and magnetic properties of the alloy was studied by means of X⁃ray diffraction and thermomagnetic curve analysis.The results show that the content of CeFe_(2) phase in the alloy decreases monotonously with the increase of La substitution,and the non⁃equilibrium specimen contains less CeFe_(2) phase than the near⁃equilibrium specimen with the same nominal composition,indicating the preparation process has a strong influence on the content of the CeFe_(2) phase.With the increase of La content,the saturation magnetization,remanence and maximum magnetic energy product of the non⁃equilibrium specimen are improved,the coercivity increases and then decreases,which all is the result of the decrease of magnetocrystalline anisotropy field and the optimization of microstructure.In addition,it is found that La con not enter CeFe_(2) phase like other rare earth metals.