磁场处理时间对铁基纳米晶磁芯磁性能的影响

Effect of magnetic field treatment time on magnetic properties of Fe-based nanocrystalline alloy magnetic cores

使用厚度为16~18μm的Fe_(73.5)Cu_(1)Nb_(3)Si_(15.5)B_(7)纳米晶带材,卷绕成47 mm×27 mm×15 mm的纳米晶环形磁芯。除合金成分外,退火工艺也直接影响磁芯性能。退火过程中的磁场时间是影响磁性能的关键因素之一。随着延长施加磁场时间,初始磁导率μ_(i)和最大磁导率μ_(m)呈现单调递减的趋势;剩磁B_(r)和矩形比B_(r)/B_(s)也呈现单调递减趋势;矫顽力H_(c)呈现单调递增的趋势。磁导率μ拐点向高频方向移动,说明在相同磁场处理温度下,延长磁场处理时间,有利于磁芯高频磁导率的提高,而且随着磁场处理时间延长,损耗、抗直流偏置能力以及在ESD试验中的稳定性也有比较明显的提高。

A nanocrystalline ring core of 47 mm×27 mm×15 mm was wound using Fe_(73.5)Cu_(1)Nb_(3)Si_(15.5)B_(7)nanocrystalline strips with thicknesses of 16-18 μm. In addition to the alloy composition, the annealing process also directly affects the core performance. The magnetic field time during the annealing process is one of the key factors affecting the magnetic properties. The initial permeability μ_(i) and maximum permeability μ_(m) show a monotonically decreasing trend as the applied magnetic field time is extended;the remanence B_(r) and rectangular ratio B_(r)/B_(s) also show a monotonically decreasing trend;the coercivity H_(c) shows a monotonically increasing trend. The inflection point of magnetic permeability μ moves toward the high frequency direction, indicating that extending the magnetizing time at the same magnetizing temperature is conducive to the improvement of the high frequency permeability of the core, and the loss, DCbias current resistance and stability in ESD test are also improved more obviously with the extension of the magnetizing time.