Abstract Fe powders based soft magnetic composites (SMCs) with organic- inorganic multiple-layer coating were fabricated by improved isolation coating followed by pressing and curing. Phosphate and organic resin were selected as the insulting layers. The influences of phosphating process and the composition of organic coating on the magnetic properties of the SMCs and soft magnetic cores have been systematically investigated. The phosphating process was modified for simple and easy operation, suitable for carbonyl iron powders with small particle size. The optimized phosphating method created a complete and continuous phosphate layer on the surface of micron sized particles. Without resin coating, the magnetic cores fabricated with the phosphated powders prepared with 0.5–0.7 wt% phosphoric acid exhibit relatively high permeability and quality factor at high frequency. In addition, a new type of mixed resin with good thermal stability was employed for insolating coating, which provides distinctly higher resistivity and better protective effect than silicone. The optimal content of the mixed resin content is about 3 wt% for fabricating the magnetic cores with low eddy current loss and hysteresis loss by producing a protective layer to isolate magnetic particles and reduce the internal stress. The SMC cores prepared with optimized phosphating process and organic coating exhibit high relative density (93.7%), high electric resistivity (2.23 × 107 Ω·cm), stable permeability (in the frequency range from 5 to 1000 kHz), high quality factor (44.8 at 700 kHz) and relatively low magnetic loss (159.0 kW/m3 at 100 kHz).

中文翻译：

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基于磷化混合树脂包覆铁粉的软磁复合磁芯工艺优化及磁性能研究

摘要 通过改进隔离涂层，然后压制和固化，制备了具有有机-无机多层涂层的铁粉基软磁复合材料（SMCs）。选择磷酸盐和有机树脂作为绝缘层。系统研究了磷化工艺和有机涂层成分对SMC和软磁芯磁性能的影响。磷化工艺经过改良，操作简便，适用于小粒径羰基铁粉。优化的磷化方法在微米级颗粒表面形成了完整且连续的磷化层。在没有树脂涂层的情况下，磁芯由磷化粉制成，0.5-0。7 wt% 的磷酸在高频下表现出相对较高的渗透率和品质因数。此外，采用新型热稳定性好的混合树脂进行绝缘涂层，其电阻率明显高于有机硅，保护效果更好。混合树脂的最佳含量为3wt%左右，通过制作保护层来隔离磁粉并降低内应力，从而制造出低涡流损耗和磁滞损耗的磁芯。采用优化磷化工艺和有机涂层制备的SMC磁芯具有高相对密度（93.7%）、高电阻率（2.23 × 107 Ω·cm）、稳定的磁导率（在5至1000 kHz频率范围内）、高品质因数（ 44.8 at 700 kHz）和相对较低的磁损耗（159.0 kW/m3 at 100 kHz）。