Study On Soft Magnetic Properties And Wide Ribbon Preparation Of New Fe-based Amorphous And Nanocrystalline Alloys

Fe-based soft magnetic nanocrystalline alloy with nano-sized grains embeded in amorphous matrix, possesses excellent soft magnetic properties:high permeability, low coercivity and low loss, is a new type of magnetic functional materials. Especially FINEMET (Fe-Si-B-Cu-Nb) alloys have exhibited wide application prospects in magnetic electronics, aerospace, defense, and so on. In present paper, the influence of minor addition of Y on composition design, thermostability and soft magnetic properties in amorphous and annealed Fe73.5Si13.5B9Cu1Nb3-xYx (x=0,1,2,3 at.%) has been investigated using X-ray diffraction (XRD), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). The amorphous ribbons were annealed at different temperatures in vacuum for 10mins. The results show that the substitution of Y enhances the thermostability of the alloy, and Fe73.5Sii3.5B9Cu1Nb1Y2 exhibits the best thermostability among them. The soft magnetic properties had also been influenced by such substitution. The most desirable soft magnetic properties are achieved for the x=2 at.% sample annealed at 700℃ for 10min, the saturation induction densities are 1.28T. A correlation between the microstructure, thermostability, and magnetic properties in amorphous and annealed ribbons has been established.Th’e article also studies the influence of addition of V on thermostability and soft magnetic properties in amorphous and annealed Fe73.5Si13.5B9Cu1Nb3-xVx (x=0,1,2,3 at.%), main conclusions are as follow:in Fe73.5Si13.5B9Cu1Nb3.xVx(x=0,1,2,3 at.%) alloys series, the thermal stability can be improved by adding moderate amount of rare earth element V, since V increases the numbers of components of alloy and the degree of mismatch between atoms, and also the nagative heats of mixing between V and other elements suppresses the atomic diffusion, in addition, V and oxygen has strong affinity, which restrain heterogeneous nucleation, and improves thermostability. The results indicate that Fe73.5Si13.5B9Cu1Nb1V2 alloy has optimal thermostability. The most desirable soft magnetic properties are achieved in Fe73.5Si13.5B9CuiNb1V1 alloy annealed at 520℃ for 10min, the saturation induction densities Bs=1.29T.In this paper, amorphous alloy wide ribbon has been preparated by single-roll spinning method. The difficulty of wide ribbon preparation lies in the control of temperature and the distance between nozzle and copper roller. Since the increase of width of ribbon. The melting-alloy pool between nozzle and copper roller is vulnerable, which is influenced by roller eccentricity, rotational speed, and molten pool surface airflow. Through practical trial and error, determining the heating power are in 30-40 kw, the distance between nozzle and roller are about 2 mm, amorphous ribbon 20 mm,50 mm wide could be successfully prepared.