Fe-Si-B-Nb-Cu-Zr非晶(纳米晶)合金的磁性机理研究

Magnetic Mechanism Study of Fe-Si-B-Nb-Cu-Zr Amorphous (Nanocrystalline)Alloy

采用单辊甩带法制取了Fe-Si-B-Nb-Cu-Zr非晶合金薄带。利用X射线衍射仪(XRD)、差示扫描量热法(DSC)和振动样品磁强计(VSM)等手段对非晶态和晶化后的薄带的微观结构和磁性能进行了表征和测试,研究了Fe-Si-B-Nb-Cu-Zr合金中磁性能随着Zr含量以及退火温度变化的磁性机理。结果表明,在铸态Fe-Si-B-Nb-Cu-Zr非晶合金中,饱和磁感应强度Bs随Zr含量的增加而减小,矫顽力Hc随Zr含量的增加而增大。经过退火处理后的Fe-Si-B-Nb-Cu-Zr合金的饱和磁感应强度变化不大,但矫顽力随着退火温度的升高先减小后增高,矫顽力在510℃退火时达到最小值,但随着温度增加矫顽力进一步增大。在510℃退火时纳米晶粒与非晶相之间的体积比达到最佳,有效各向异性<K>最小,软磁性能最好。

Fe-Si-B-Nb-Cu-Zr amorphous alloy ribbons were prepared by melt spinning.The microstructure and magnetic properties of the amorphous and annealing alloys were investigated by X-ray diffractometer（XRD）,differential scanning calorimetry（DSC）and vibrating sample magnetometer（VSM）.The magnetic mechanism of Fe-Si-B-Nb-Cu-Zr alloys is investigated with the variation of annealing temperature.The results show that the saturation induction densities（Bs）decrease as the Zr content increases in the as-cast Fe-Si-B-Nb-Cu-Zr alloys,and that the coercivities（Hc）increase with the increasing Zr content.The saturation induction densities（Bs）of Fe-Si-B-Nb-Cu-Zr alloys are steady after annealing,but the coercivity first decreases and then increases as the annealing temperature increases.After annealing at 510 ℃,the coercive force shows a minimum value.Then the coercive force increases with the increasing annealing temperature.The magnetic mechanism of Fe-Si-B-Nb-Cu-Zr alloys is discussed within the frame of the two-phase random magnetic anisotropy model.When the annealing temperature is 510 ℃,the volume ratio between nanocrystals and amorphous phase reaches the best value,the effective anisotropy K reaches the minimum value,and the coercive force is the lowest.