Fe基合金的微结构与频率特性

Microstructure and Frequency Properties in Fe-based Alloys

用高能球磨的方法制备铁基纳米晶铁钴和铁镍合金,研究材料的结构与频率特性。结果表明:具有体心立方晶体结构样品的颗粒尺寸在0.5～5μm之间,尺寸分布较宽;而具有体心立方和面心立方混合晶体结构样品的在5～20μm之间,尺寸分布较窄。含钴样品的钴含量有提高样品截止频率的作用;样品的磁导率实部在掺杂量为7.69%(原子分数)时均出现极大值。Co掺杂的样品显示出弛豫型磁谱特征,而Ni掺杂样品则显示出共振型磁谱特征。Fe-Co样品在高频区域磁导率虚部随着掺杂量的增大而减小,同时随着掺杂量的增加,磁导率虚部最小值向高频区域移动。Fe-Ni样品的磁导率虚部最小值也随着掺杂量的增加向高频区域移动。纯铁样品则在高频区域磁导率虚部小于掺杂样品。

Fe-based alloys Fe-Ni and Fe-Co,with a nanostructure,are fabricated by high-energy milling,and their structure and frequency properties are studied.The particle size of samples with body-centered cubic grain structure is 0.5-5μm,while that of samples with body-centered cubic and face-centered cubic grain structure is 5-20μm.The Co-doping increases the threshold frequency for Fe-Co.The pure Fe and Fe-Ni samples have a resonant characteristic in the real component curve of A.C.permeability,while the Co containing ones show a relaxant behavior.Fe-7.69%Ni or Fe-7.69%Co（atom fraction）,the real component of ac permeability reaches a maximum.At high frequency,the imaginary component of A.C.permeability increases with decreasing of Co-doping for Fe-Co,and the minimum of imaginary component shifts to higher frequency with Co increasing.The minimum of imaginary component also shifts to higher frequency with Ni increasing for Fe-Ni,and pure Fe has a lower imaginary component than doping samples.