掺杂Co元素Fe-6.5wt%Si磁粉芯制备及性能研究

发布时间：2018-08-09 15:30

【摘要】：摘要：Fe-6.5wt%合金软磁性能优异。合金磁晶各向异性常数K1约为3%Si-Fe合金的一半,磁致伸缩系数λs几乎为零,铁损较低。但由于其室温脆性和低的热加工性能,冷轧和常规热轧方法均难以将板坯直接加工成能实际应用的薄带或板材,严重制约了其在工业领域的发展。且由于合金含硅量较高(硅为抗磁性物质),铁硅合金饱和磁感应强度Bs大大降低,难以满足目前仪器设备的大功率容量和小型轻便化发展要求。添加合金元素Co可显著提高Fe-6.5wt%Si合金的饱和磁感应强度Bs,改善其软磁性能。本研究采用惰性气体雾化法成功制备了Fe100-xCox-6.5wt%Si (x=0,1,3,5,7,10,15,35,50)合金粉末并通过后续工艺制备了Fe100-xCox-6.5wt%Si磁粉芯,对粉末制备工艺、绝缘包覆、退火热处理以及合金成分对磁粉芯性能的影响做了相关的研究。在合金熔体过热100-200℃,雾化压力为6MPa条件下,采用气雾化法在Fe-6.5wt%Si基础上添加Co元素成功制备了Fe100-xCox-6.5wt%Si三元合金粉末。结果表明：本实验所采用雾化工艺较稳定,雾化粉末成分与名义成分偏差小,碳氧含量低,颗粒球形度高、表面光洁卫星球少,且其粒度分布范围较宽呈单峰分布；雾化Fe100-xCox-6.5wt%Si粉末具有α-Fe相结构,衍射谱中没有观察到DO3有序相独立特征峰；不同Co含量对Fe-6.5wt%Si合金饱和磁化强度影响不同,Fe90Co10-6.5wt%Si合金粉末饱和磁化强度Ms值最高,其Ms达到219.26emu/g。采用偶联剂+硅酮树脂绝缘剂包覆,磁粉表面均匀的覆盖了一层较薄绝缘层。对比采用磷酸钝化+硅树脂与采用偶联剂+硅树脂包覆Fe-6.5wt%Si磁粉芯在f=50kHz, Bm=0.1T条件下磁性能,发现采用1%ATPS偶联剂+4%DC-805硅酮树脂包覆磁粉芯综合性能较佳。由于磁粉颗粒尺寸大小分布不太均匀,颗粒间存在有孔隙,磁粉芯生坯密度相对较低,致密化程度不高。随退火温度升高,粉末颗粒间包覆剂逐渐减少,但磁粉芯断面没有观察到明显绝缘剂“烧蚀”现象,磁粉表面绝缘层保持相对完好。不同Co元素含量Fe100-xCox-6.5wt%Si磁粉芯磁性能参数随退火温度升高变化规律不同,400-800℃退火过程中,磁粉芯磁导率u。以Fe100-xCox-6.5wt%Si (x=1,3,5)磁粉芯较高,以Fe100-xCox-6.5wt%Si (x=35,50)较低；磁粉芯矫顽力Hc以Fe100-xCox-6.5wt%Si (x=0,1,3,5,7)磁粉芯较低,且均在500℃退火时达到谷值；磁粉芯损耗Ps以Fe100-xCox-6.5wt%Si (x=0,1,3,5)磁粉芯随退火温度升高变化范围相对较小,损耗值较低。粉末性质对磁粉芯直流性能影响较大,添加适量Co可显著改善磁粉芯交、直流性能。相同频率下,Fe95Co5-6.5wt%Si磁粉芯有效磁导率最高,且其损耗明显低于Fe-6.5wt%Si磁粉芯；而Fe93Co7-6.5wt%Si磁粉芯直流磁性能较好,其饱和磁感应强度Bs=1.7179T。综合比较,Fe95Co5-6.5wt%Si磁粉芯具有较优异的综合软磁性能。
[Abstract]:Fe-6.5wt% alloy has excellent soft magnetic properties. The magnetocrystalline anisotropy constant K1 is about half of the 3%Si-Fe alloy, the magnetostrictive coefficient is almost zero, and the iron loss is low. But because of its brittle and low hot working properties at room temperature, the cold rolling and conventional hot rolling methods are difficult to directly process the slab into thin strips or plates that can be applied to the actual application. Because of the high silicon content of the alloy (silicon as an anti magnetic material), the saturation magnetic induction intensity Bs of the ferrosilicon alloy is greatly reduced, and it is difficult to meet the high power capacity and small portable development requirements of the current instrument and equipment. Adding alloy element Co can significantly improve the saturation magnetic induction intensity of Fe-6.5wt%Si alloy Bs. In this study, Fe100-xCox-6.5wt%Si (x=0,1,3,5,7,10,15,35,50) alloy powder was successfully prepared by inert gas atomization and Fe100-xCox-6.5wt%Si magnetic powder core was prepared by subsequent process. The effects of powder preparation, insulation coating, annealing treatment and alloy composition on the properties of magnetic powder core were made. Research.
Under the condition that the alloy melt overheated 100-200 C and the atomization pressure was 6MPa, the Fe100-xCox-6.5wt%Si three element alloy powder was successfully prepared by adding Co element on Fe-6.5wt%Si based on the aerosol method. The results showed that the atomization technology was more stable, the composition of the atomized powder and the nominal composition were small, the carbon and oxygen content was low, and the sphericity of the particles was low. The surface light and clean satellite balls are small, and the size distribution of the Fe100-xCox-6.5wt%Si powder has a single peak distribution, and the atomized Fe100-xCox-6.5wt%Si powder has a -Fe phase structure. The independent characteristic peak of the ordered phase is not observed in the diffraction spectrum; the different Co content has different influence on the saturation magnetization of the Fe-6.5wt%Si alloy, and the saturation magnetization M of the Fe90Co10-6.5wt%Si alloy powder M The s value is the highest, and its Ms reaches 219.26emu/g.
The magnetic properties of the magnetic powder coated with the coupling agent and silicone resin insulating agent covered a thin layer of insulation. The magnetic properties of the magnetic powder core coated with the coupling agent + silicon resin and the Fe-6.5wt%Si magnetic powder core coated with the coupling agent + silicon resin were compared. The comprehensive properties of the magnetic powder core coated with the 1%ATPS coupling agent +4%DC-805 silicone resin were found. Better.
Because the size distribution of magnetic powder particles is not uniform, there are pores between particles, the density of magnetic powder core green is relatively low, and the densification degree is not high.
With the increase of annealing temperature, the coating agent of powder particles decreases gradually, but there is no obvious "ablation" phenomenon in the magnetic powder core section, and the surface insulation of magnetic powder remains relatively intact. The magnetic parameters of the magnetic powder core of different Co elements are different with the annealing temperature. During the annealing process at 400-800, the magnetic particles are magnetic. The core magnetic permeability U. is high in Fe100-xCox-6.5wt%Si (x=1,3,5) magnetic core and low in Fe100-xCox-6.5wt%Si (x=35,50), and the magnetic core coercive force Hc is low in Fe100-xCox-6.5wt%Si (x=0,1,3,5,7) magnetic core, and all reaches the valley value at 500 C. The magnetic core loss Ps with Fe100-xCox-6.5wt%Si (x=0,1,3,5) magnetic core increases with the annealing temperature. The range of change is relatively small and the loss value is low.
The properties of powder have great influence on the DC performance of magnetic powder core. Adding a proper amount of Co can significantly improve the magnetic core AC and DC performance. Under the same frequency, the Fe95Co5-6.5wt%Si magnetic core has the highest effective permeability, and its loss is obviously lower than the Fe-6.5wt%Si magnetic core; while the Fe93Co7-6.5wt%Si magnetic core has a better direct current magnetic performance and its saturation magnetic induction intensity Bs=1.7179T.. The results show that Fe95Co5-6.5wt% Si core has excellent soft magnetic properties.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM271.2

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