Preparation And Properties Of Oriented Bulk Co-based Amorphous Soft Magnetic Composites

In recent years,electronic power devices led by technology have developed in the direction of high frequency,miniaturization,energy saving,and high performance.At present,the demand for amorphous powder cores in the fields of 5G communication power supply,vehicle power supply,5G base station and 3C electronic products is growing rapidly,and amorphous soft magnetic composite materials have become one of the key areas of focus in the materials industry.Amorphous soft magnetic composites,have excellent comprehensive properties.It is very important to develop amorphous soft magnetic composites with high frequency,high power and low loss.The traditional amorphous soft magnetic composites are prepared based on powder metallurgy technology.It is difficult to realize most anisotropic structures in the same direction between powder particles,resulting in low magnetic properties.As a new type of soft magnetic materials,to solve this problem,the structure of the amorphous soft magnetic composites is redesigned in this paper.The thin amorphous ribbon is used as the magnetic core material,and the ordered structure is realized by the magnetic field heat treatment orientation process,and the oriented structure is prepared by the spark plasma sintering technology.of amorphous soft magnetic composites.Sintered layered soft magnetic composites is a promising material,which can be used in high-frequency applications,induction motors and other types of motors.In order to study soft magnetic composites prepared based on ribbons,the main research contents of this paper are as follows:The magnetic field heat treatment device is independently designed,and the amorphous strips are oriented by longitudinal magnetic field heat treatment.Fine grains with uniform particle size of about 2 nm were obtained,and the in-plane lattice deflection direction achieved a partially parallel anisotropic structure and excellent soft magnetic properties.After 215°C and 9600 A/m longitudinal magnetic field heat treatment,the initial magnetic permeability of the samples reached 11900,and the coercivity was as low as 0.54 A/m.The soft magnetic properties improved with the increase of the external magnetic field and finally tended to be constant.In this paper,a uniform and dense composite insulating layer with Si O₂as the outer layer and Fe₂O₃and Co₃O₄as the inner layer thickness of about 2?m is prepared by oxidation method,so that the surface of the strip has a high resistivity of M?level,which can significantly reduce the softness under high frequency.loss of magnetic material.Then,the amorphous soft magnetic composite material with layered orientation structure was prepared by spark plasma sintering technology.The electromagnetic and mechanical properties of the sintered block samples in different directions,such as permeability and resistivity,were investigated.Through the resistivity tests in different directions,it is found that the lateral resistivity of the amorphous soft magnetic composite material is higher than the longitudinal resistivity.The transverse resistivity reaches 2.5×10⁴??·cm,the aspect ratio reaches 1:120,and the longitudinal magnetic properties are better than the transverse magnetic properties.The results show that the amorphous soft magnetic composites prepared by orientation-optimized SPS sintering can achieve vertical electromagnetic orientation with high magnetic permeability in the direction of the magnetic circuit and high resistance in the direction of the magnetic circuit.