气雾化法制备Fe-6.5%Si-x%Ni合金粉末及其性能的研究

Performance Characterization of Gas-Atomized Fe-6.5%Si-x%Ni Powders

采用气雾化法制得了Fe-6.5%Si-x%Ni(x=0,0.2,0.5,0.8,1.0;质量分数)金属软磁合金粉末,对合金粉末进行绝缘包覆处理后压制成磁粉芯进行磁性能检测,磁粉芯尺寸为27 mm×15 mm×5 mm,压制压力为1 GPa。利用激光粒度分析仪、扫描电子显微镜(SEM)、X射线衍射仪(XRD)和软磁交流分析仪对粉末的粒度分布、形貌、相组成和磁性能进行检测和分析。结果表明:在雾化过程中,随着Ni元素添加量的增加,金属液粘度增加,雾化时间变长,粉末颗粒尺寸增大,中位径d50从21.04μm增大到38.62μm;粉末为球形或近球形,部分粉末表面有卫星球;粉末为单相α-Fe相,表明Ni元素以固溶体形式溶入基体晶格,造成晶格畸变,增加了合金粉末的内应力;随着Ni元素含量的升高,矫顽力先升高后降低,添加1.0%Ni时为最优值307.9 A·m-1(0.05 T,100 k Hz),振幅磁导率先降低后升高添加1.0%Ni时为最优值15.7(0.05 T,100 k Hz),且在频率达到80 k Hz时略有升高,磁损耗先升高后降低,在添加1.0%Ni时为最优值4595 m W·cm-3(0.05 T,100 k Hz)。

Fe-6.5% Si-x% Ni （x = 0, 0.2, 0. 5, 0.8, 1.0 ; mass fraction） soft magnetic alloy powders were produced by gas atomi- zation technology and pressed into magnetic cores for magnetic properties detection. The size of the cores was 27 mm × 15 mm × 5 mm and the pressing pressure was 1 GPa. Laser particle size analyzer, scanning electron microscopy （SEM）, X-ray diffraction （XRD） and soft magnetic AC analyzer were used to detect and analyze the particle size diffraction, morphology, phase composition and magnetic properties. The results showed that, in the process of atomization, the atomization time increased with the increase of the amount of Ni addition due to the improvement of viscosity of the alloy. And the particle size increased with the increase of the amount of Ni addition, and the median diameter increased from 21.04 to 38.62 μm. The powders were smooth and spherical in shape with a few satellite balls cladded to the surface, α-Fe diffraction peaks were the single phase found in the powders which indicated that Ni atoms got into the base iron lattice as solid solution. The coercive force rose first and fell later and the best value was 307.9 A.m-1 with 1.0% Ni addi- tion at 0.05 T and 100 kHz. The amplitude permeability fell first and rose later and the best value was 15.7, which was acquired with 1.0% Ni addition at 0.05 T and 100 kHz. The magnetic core loss rose first and fell later and the best value was 4595 mW.cm -3, with 1.0% Ni addition at 0.05 T and 100 kHz.