| The soft magnetic composite is an important soft magnetic material,which is widely used in various electronic components.As the frequency of use of soft magnetic cores gradually develops toward higher frequencies,eddy current losses are also significantly enhanced,greatly reducing the overall performance of soft magnetic materials.At the same time,the soft magnetic material has low plastic toughness,almost zero elongation,difficult rolling and forming,and production and application are restricted.Therefore,while perfecting the basic research of the existing process,explore new soft magnetic materials research ideas and preparation methods,while ensuring good magnetic properties and effectively reducing the high-frequency eddy current loss of the soft magnet core.In this paper,iron-based alloy powder(Fe-6.5wt.%Si alloy powder and Fe Si Al alloy powder)is used as the research object,and the iron-based soft magnetic composite is prepared by fluidized chemical vapor deposition(FCVD)process combined with spark plasma sintering(SPS).The phase composition and microstructure of the composite powder and composite iron core are analyzed,and the influence of the insulating layer between the iron-based alloy particles on the electrical and magnetic properties of the soft magnet core is studied.The specific research results are as follows:1.In the prepared soft magnetic composites,Fe-6.5wt.%Si particles are uniformly and densely surrounded by the Si O2 insulating layer.Compared with the Fe-6.5 wt.%Si soft magnetic core without an insulating layer,while increasing the resistivity of the soft magnetic core,it limits the radius of the eddy current and greatly reduces the iron loss of the core.The soft magnetic composite prepared by the FCVD method used in this paper has excellent electromagnetic characteristics such as high magnetic inductance,high resistivity,good frequency stability,low coercivity,and low iron loss,saturation magnetic induction intensity is 179.4 emu·g-1,coercive force is 15 Oe,in the middle and high frequency range,the relative permeability is relatively stable,about 161,The resistivity is 66??·m,and the iron loss of P1 T/10 k Hzis only 6.5 W·kg-1.2.Based on the above process,by changing the deposition temperature,the effect of the deposition temperature on its microstructure and electromagnetic properties was systematically studied.The results show that the effect of the deposition temperature on the thickness of the Si O2 coating layer increases first and then decreases.The formation of the internal structure of the Fe-6.5 wt.%Si/Si O2 soft magnetic composites can be well controlled by adjusting the deposition temperature.At the same time,the deposition temperature has a certain effect on the thickness of the coating layer and the electromagnetic characteristics of the soft magnet core.When the deposition temperature is 700?,the Fe-6.5 wt.%Si/Si O2 soft magnetic composite iron core with a thickness of 1550 nm Si O2 cladding layer has the best magnetic properties:the saturation magnetic induction intensity is 161.05 emu·g-1,The coercive force is 16 Oe,the magnetic moment is 1.19 T-1,the resistivity is 94??·m,the iron loss of P10 m T/100 k Hzis only 82.02 W·kg-1.3.Through the above process,the Fe Si Al/Si O2 soft magnetic composite iron core was successfully prepared,and then by controlling the sintering temperature to the reaction temperature,during the high temperature sintering process,the Al in the Fe Si Al alloy powder and the Si O2 coated on the surface of the Fe Si Al alloy were replaced,and finally formed Fe3Si/Al2O3soft magnetic composite iron core.The microstructure and electromagnetic properties of the three soft magnetic cores are compared and studied.The results show that the three cores have excellent electromagnetic properties.The relative permeability of the two composite cores is much lower than that of the original Fe Si Al core and the high frequency stability is better.In addition,the soft magnetic composite iron core also shows the trend of decreasing density and increasing resistivity.The loss of the two has also improved significantly.And their iron loss of P10 m T/200 k Hz respectively are 421.18W·kg-1,508.32W·kg-1,compared with the original Fe Si Al iron core,the decrease rate reached28.57%and 13.79%respectively. |
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