Magnetic properties and domain patterns of amorphous powder cores produced by the cold-pressing

以玻璃为粘结剂，采用冷压烧结工艺，在低于晶化温度的高温下烧结，制备了非晶Fe-Cr-Si-B-C粉芯。所获得的芯的密度为约80%。测量了直径为30 mm的环形样品的磁性能。对于在2GPa、室温下压制并在空气中460℃×20 min烧结的磁芯，在Hm = 5 MoE的频率范围内，直到1 MHz的初始磁导率约为100，在Bm = 0.1 T的频率范围内，100 kHz的磁芯损耗为500 kW/m^3。这些值与先前报道的热压无定形粉末芯的值相当。与广泛用于扼流线圈和回扫变压器的商用Sendust粉芯相比，初始磁导率大致相等，铁损降低30%。此外，还观察到了非晶磁芯的磁畴图案，并讨论了它们与磁性能的关系。

Amorphous Fe-Cr-Si-B-C powder cores with glass binders were produced by cold-pressing and sintering at relatively high temperatures below crystallization temperature. The density of the core obtained was about 80%. The magnetic properties of toroidal samples 30 mm in diameter were measured. For the core pressed at 2 GPa, room temperature and sintered at 460℃×20 min in air, the initial permeability in the frequency range up to 1 MHz for Hm = 5 mOe was about 100, and the core loss at 100 kHz for Bm = 0.1 T was 500 kW/m^3. These values were comparable with those of hot-pressed amorphous powder cores, which had been previously reported. Compared with a commercial Sendust powder core widely used for choking coils and fly-back transformers, the initial permeability was approximately equal and the core loss was 30% lower. Furthermore, the domain patterns of the amorphous core were observed and their relation to the magnetic properties was discussed.