Study On Preparation And Soft Magnetic Properties Of Fe-based Amorphous Ribbons And Powder Cores

Firstly, Fe_73.5Cu₁Nb₃Si_13.5B₉ amorphous ribbons were prepared by single rolling, micro-analysis displayed, the nanocrystallization temperature of amorphous ribbons was 530℃, ribbons generated a solid solution which main phase was α-Fe (Si) with the grain size was about 25.57nm after being annealed at 500℃ for lh. as the nanocrystallizatin degree of amorphous ribbons increased, the microhardness and soft magnetic properties of amorphous ribbons were also improved, after ribbons were annealed at 500℃ for lh, the microhardness got maximum, the value was HV946.1 , and the direct current soft magnetic properties were optimum after ribbons were annealed at 500 ℃ for 2h, the initial permeability μ_i was 107600 , maximum permeability μ_m was 662600, saturation induction B_m was 1.3T, remnent magnetism B_r was 0.828T, meanwhile, coercive force H_c and magnetic hysteresis loss P_u were little, hysteresis cycle was high rectangle status, in addition, brittle experiment indicated: The critical brittle temperature of ribbons was 250℃, there was a critical brittle time when annealing temperature was definite, when holding time was shorter than critical brittle time ,the brittle degree increased gradually as holding time increased. When holding time met critical brittle time, the brittle degree of ribbons was stable. The best brittle annealing of ribbons was: being annealed at 250℃ for lh, and then being annealed at 300℃ for 1h.Secondly, brittle amorphous ribbons were ball milled to amorphous powder, and amorphous powder coated with adhesives was pressed into magnetic powder cores, at the same molding condition , the finer of amorphous powder was, the higher densification of powder cores was, in the experiment, the densification of 300 mesh powder cores was highest, then 100 mesh (15vol%) +200 mesh (35vol%) +300 mesh (50vol%) powder cores, the densification of 100 mesh powder cores was lowest; annealing could improve the soft magnetic properties of powder cores distinctly, as for 300 mesh powder cores, when holding time was 0.5h²h, the initial permeability μ_i and quality factor Q were increased gradually as the increasing of annealing temperature, after being annealed at 500℃ for 1h , μ_i got maximum, the value was...