雾化法制备的Fe基非晶/纳米晶软磁合金粉末:特点、方法及研究进展

在我国“碳达峰,碳中和”和世界能源大变革的重大战略背景下,以光伏、风力发电和新能源为代表的领域蓬勃发展,这对电子元器件提出了可承受大电流、大功率的要求。磁粉心是指对金属软磁粉末进行绝缘包覆,然后通过模压成型和退火热处理后得到的一类软磁复合材料。磁粉心具有饱和磁感应强度高、温度稳定性好、直流偏置性能优异等特点,已广泛应用于光伏、风力发电和新能源装备中。Fe基非晶/纳米晶合金软磁性能优异、经济性好,在制备高性能磁粉心领域有广阔的前景。Fe基非晶/纳米晶合金粉末的制备方法通常为机械破碎法和雾化法,其中雾化法具有适宜大规模生产、污染小、成本低等优点。然而,由于Fe基非晶材料的非晶形成能力较低,使用雾化法来制备软磁性能好、批次稳定性高的Fe基非晶/纳米晶粉末存在着较大的困难和瓶颈。概述了非晶/纳米晶材料的微观组织特征和形成机制,以及雾化法制备金属粉末的机理。最后,分析了雾化法制备Fe基非晶/纳米晶软磁合金粉末的研究现状,以期为后续研究和发展提供参考。

热喷涂Fe基非晶/纳米晶涂层的研究进展

分别介绍了等离子喷涂、高速火焰喷涂、活性燃烧高速燃气喷涂以及电弧喷涂技术制备Fe基非晶/纳米晶涂层的研究现状,分析比较了各自的特点、工艺方法、优缺点等,并展望了其发展前景。

Long-term corrosion behavior of HVOF sprayed FeCrSiBMn amorphous/nanocrystalline coating

A FeCrSiBMn amorphous/nanocrystalline coating with 700 μm in thickness and 0.65% in porosity, was prepared by high velocity oxygen fuel(HVOF) spraying process. The long-term corrosion behavior of the FeCrSiBMn coating was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy(EIS) tests in a 3.5% NaCl solution with a hard chromium coating as a reference. The FeCrSiBMn coating exhibited higher corrosion potential and lower corrosion current density than the hard chromium coating. The pore resistance(Rp) and charge transfer resistance(Rct) of FeCrSiBMn coating were higher than those of the hard chromium coating. In addition, after immersion in the Na Cl solution for 28 d, only small pores in the FeCrSiBMn coating were observed. All the results indicated that the FeCrSiBMn coating held superior corrosion resistance to the hard chromium coating. This could be attributed to the dense structure, low porosity and amorphous/nanocrystalline phases of the FeCrSiBMn coating.