The current trend toward the rise in the operating frequency in power electronics allows a dramatic miniaturization of power converters but requires reliable passive components. Spinel ferrites could be appropriate magnetic materials for transformers and inductors, within the range 0.5–5 MHz, providing that power core loss, enhanced by the frequency rise, remains low. This work investigates the opportunity to shape magnetic cores by powder injection molding (PIM), while keeping a low power dissipation in components. It paves the way for designing new core geometries incorporating additional functions such as thermal management. A commercial Mn–Zn granulated ferrite powder was used in this study. The densification state of the ferrite feedstock (wax binder system) was investigated after injection and debinding in samples (ring-shaped cores) sintered with different temperatures: 1140 °C/4 h, 1145 °C/4 h, 1150 °C/4 h, 1155 °C/4 h, and 1160 °C/4 h. A Low carbon content (<100 ppm) was confirmed by Instrumental Gas Analysis (IGA) and X-ray diffraction (XRD) analysis revealed that the spinel phase formation was fully achieved after sintering. Core losses data (from 100 to 900 kHz at 50 mT) at different temperature (from room to 110 °C) were analyzed by separating the contributions of the hysteresis ( $P_{h} \sim A.f$ ), eddy current ( $P_{e} \sim B.f ^{2}$ ), and residual ( $P_{r} \sim C.f_{n}$ , with $n >2$ ) losses. The evolution of the total power losses ( $P_{t}$ ) for toroids made by PIM was compared to the ones of samples fabricated by uniaxial compression (UC). It appears that the losses by hysteresis were always lower for PIM than for UC, whereas it was the opposite for eddy current and residual losses. Microstructural analyses showed that open porosity plays an important role in this behavior.

中文翻译：

---

电力电子粉末注射成型软铁氧体材料

当前功率电子器件工作频率上升的趋势允许功率转换器显着小型化，但需要可靠的无源元件。尖晶石铁氧体可能是适用于变压器和电感器的磁性材料，在 0.5-5 MHz 范围内，前提是由于频率上升而增加的功率磁芯损耗保持较低。这项工作研究了通过粉末注射成型 (PIM) 成型磁芯的机会，同时保持组件的低功耗。它为设计包含热管理等附加功能的新磁芯几何形状铺平了道路。本研究中使用了商用锰锌粒状铁氧体粉末。研究了在不同温度下烧结的样品（环形芯）中注射和脱脂后铁氧体原料（蜡粘合剂系统）的致密化状态：1140 °C/4 h、1145 °C/4 h、1150 °C/4小时、1155 °C/4 小时和 1160 °C/4 小时。仪器气体分析 (IGA) 和 X 射线衍射 (XRD) 分析证实了低碳含量 (<100 ppm)，表明在烧结后完全形成了尖晶石相。通过分离磁滞的贡献来分析不同温度（从室温到 110 °C）下的磁芯损耗数据（从 100 到 900 kHz，50 mT）。100 ppm) 通过仪器气体分析 (IGA) 和 X 射线衍射 (XRD) 分析证实，表明在烧结后完全实现了尖晶石相的形成。通过分离磁滞的贡献来分析不同温度（从室温到 110 °C）下的磁芯损耗数据（从 100 到 900 kHz，50 mT）。100 ppm) 通过仪器气体分析 (IGA) 和 X 射线衍射 (XRD) 分析证实，表明在烧结后完全实现了尖晶石相的形成。通过分离磁滞的贡献来分析不同温度（从室温到 110 °C）下的磁芯损耗数据（从 100 到 900 kHz，50 mT）。 $P_{h} \sim Af$ ), 涡流 ( $P_{e} \sim Bf ^{2}$ ) 和残差 ( $P_{r} \sim C.f_{n}$ ， 和 $n >2$ ) 损失。总功率损耗的演变（ $P_{t}$ ) 由 PIM 制造的环形线圈与通过单轴压缩 (UC) 制造的样品进行比较。看来，PIM 的滞后损耗总是低于 UC，而涡流损耗和残余损耗则相反。微观结构分析表明，开放孔隙度在这种行为中起着重要作用。