气雾化法(Fe_(1-x)Co_x)_(93.5)Si_(6.5)软磁合金粉末的显微组织与磁性能

采用气雾化法制备了(Fe_(1-x)Co_x)_(93.5)Si_(6.5)(x=0,0.01,0.03,0.05,0.07,0.1,wt%)系列合金粉末,利用扫描电镜、X射线衍射仪和振动样品磁强计等分析检测手段研究了合金粉末显微组织和磁性能。结果表明,气雾化合金粉末球形度好,表面光洁,组织均匀,合金为单一的α-Fe(Si)相;掺杂Co元素不改变Fe_(93.5)Si_(6.5)合金粉末显微结构,但提高了合金比饱和磁极化强度。当x=0.1时,合金粉末比饱和磁极化强度σ_s达到最大值219.26 A·m~2/kg,其原因为Fe-Co原子间的交换耦合作用使得单原子波尔磁矩达到最大。粉末矫顽力随Co含量的增加单调递增,这主要归因于Co原子磁晶各向异性常数K_1远大于Fe,导致其矫顽力增大。总体而言,(Fe_(0.9)Co_(0.1))_(93.5)Si_(6.5)合金粉末磁性能较优异。

Microstructure and magnetic properties of (Fe1-xCox)93.5Si6.5 magnetic powders prepared by gas atomization

(Fe1-xCox)93.5Si6.5 alloy powders were prepared by gas atomization. The microstructure and magnetic properties of Co-added series of Fe93.5Si6.5 alloy powders were analyzed by scanning electron microscopy, X-ray diffraction, and vibrating sample magnetometer, respectively. The results show that the powders is of ball shape with smooth surface and uniform microstructure, and only singleα-Fe(Si) phase was observed; Co adding can effectively increase the specific saturation polarization, however, it does not change the Fe93.5Si6.5 alloy phases. With Co addition up tox=0.1, specific saturation polarization reaches the maximum value of 219.26emu/g, which can be attributed to the exchange coupling effect between Fe-Co atoms,resulting in highest monatomic Bohr magnetic moments. The coercive force of the powders increases monotonically with the Co content, which could be correlated with the fact that the crystalline anisotropyK1 of Co is higher than that of Fe,leading to higher coercivity of the alloy. To sum up, the (Fe0.9Co0.1)93.5Si6.5 alloy powders has better magnetic properties.