Preparation Of Fe-based Nanocrystalline Soft Magnetic Materials With High Saturation Magnetization

Fe based nanocrystalline soft magnetic alloy has the advantages of high saturation magnetic induction intensity,low force,low loss and so on.To nanocrystalline alloy strip saturation magnetization intensity is not high enough,strip width is limited,and poor toughness consistency is an urgent need to solve the technical problem,this paper studies alloy mother alloy composition design and annealing heat treatment,etc.,using atom probe tomography technology such as atomic analysis method,research from amorphous to amorphous nanocrystalline alloy mixed state evolution process and its crystal structure with thin brittle,magnetic effects.At the same time,the origin of the high saturation magnetic induction intensity obtained by nanocrystalline alloy was studied,and the influence law of the proportion and size of amorphous phase and crystallized phase on the magnetic properties of thin strip was established.In this paper,through the substitution and addition of transition group metal elements V,P and C,the composition of the alloy was optimized,and the amorphous forming capacity,crystal structure and soft magnetic properties of the alloy were studied.By changing the annealing process of heat treatment,the combined structure and magnetic properties of the amorphous phase and nanocrystalline phase of the rapidly quenched thin strip were regulated.The specific contents and main conclusions are as follows:(1)When the Fe-based amorphous alloy is replaced by V as Nb,the amorphous forming capacity of the alloy decreases;However,the increase of ?Tp of the alloy is conducive to the stability of nanocrystalline structure;After annealing with the same process parameters and replacing Nb with V,the coercive force did not change significantly,but the saturation magnetic induction intensity increased significantly.When V completely replaced Nb,the saturation magnetic induction intensity was 187.2emu/g.(2)The P and C elements in the Fe-based amorphous alloy are excluded from the enriched Fe region,and the grains are enriched in the amorphous matrix to cover the grains,so as to control the growth of the αFe-(Si)grain.P element can improve the amorphous forming capacity of the alloy,while C element can improve ?Tp,which is conducive to the stability of nanocrystalline structure.(3)microwave annealing can make the αFe-(Si)grain nucleate rapidly,so as to improve the saturation magnetic induction intensity of the amorphous alloy strip;The stress generated by fast nucleation of αFe-(Si)grain in the alloy increased the coercivity of the alloy after a short time of microwave annealing.The optimal soft magnetic performance with a saturation magnetization of 193emu/g was obtained by 1000 W microwave annealing for 10 min.