最新色国产精品精品视频,中文字幕日韩一区二区不卡,亚洲有码转帖,夜夜躁日日躁狠狠久久av,中国凸偷窥xxxx自由视频

In this thesis, Fe-Si system metal magnetic powder core was prepared from flaky Fe₉₅Si₁B₂P_0.5Cu_1.5 alloy powders instead of the spherical Fe-6.5%Si alloy powders. Firstly, the preparation of Fe₉₅Si₁B₂P_0.5Cu_1.5 alloy powders and Fe₉₅Si₁B₂P_0.5Cu_1.5 magnetic powder core were studied, and then the influences of annealing temperature and forming pressures on soft magnetic properties of the magnetic powder core were systematically investigated. Research showed that the permeability (μe) of Fe₉₅Si₁B₂P_0.5Cu_1.5 magnetic powder core had optimal stability of frequency in the frequency range of 1~200kHz. Residual internal stress produced in the pressing process was fully released after annealing at 450℃ for 1h, which could significantly improve the permeability (μe) of the magnetic powder core, and the maximum value was 53 with a forming pressure of 1.74GPa. With the increase of the applied DC magnetic field level, the permeability of the magnetic powder core decreased gradually. When DC magnetic field levels(H) was 50Oe, the percentage permeability of the magnetic powder core remain higher than 70%, As H increase to 130Oe, the permeability of magnetic powder core was still greater than 20. This showed that Fe₉₅Si₁B₂P_0.5Cu_1.5 magnetic power core had optimal DC-bias property.