Study On The Heat Treatment Process And Properties Of Fe-based Nanocrystalline Magnetic Cores

Iron-based Amorphous Nanocrystalline Alloys with high permeability,low coercive,high magnetic flux,low cores-loss as the best soft magnetic materials are widely used.In the production, the heat treatment process is the key factors which influence the properties of soft magnetic alloy and its production in the process of heat treatment energy is large.Therefore, it’s of great significance to optimize the heat treatment process.The study of this paper is using the strips with the width of (5-50) mm and the thickness of (25-35) u m are taken as samples, then they are coiled to the magnetic cores.Combined with the actual production of the enterprise,we make the vacuum heat treatment,nitrogen protection,heat treatment and rapid heat treatment and achieve the best thermal treatment technology. Comparing the influence of the three different technology of heat treatment on the trips properties.The results show that, the best common vacuum heat treatment process of Iron-based amorphous nanocrystalline core with1℃/min rate to annealing temperature.When the heat treatment process of amorphous strips is540℃X60min and the tapping temperature is200℃,the permeability μ e=73670(f=1kHz).the best nitrogen protection heat treatment process of Iron-based amorphous nanocrystalline core with1℃/min rate to annealing temperature.When the heat treatment process of amorphous strips is550℃×60min and the tapping temperature is200℃,the permeability μ e=103770(f=1kHz). The performance of the heat treatment under nitrogen protection is higher than ordinary vacuum heat treatment.The influences of fast heating rate and different tapping temperature for the soft-magnetic properties of the Fe-based amorphous and nanocrystalline Strip are studied. The results show that the initial temperature is480℃,and with1℃/min rate to annealing temperature.When the heat treatment process of amorphous strips is540℃×60min and the tapping temperature is200℃, the soft magnetic properties of which are the best, such as μ e=66340、P i=101800、Bs=1.157T、Hr=0.6781A/m、 Hc=0.6434A/m (f=1kHz). they don’t appear to be much different from the common ’vacuum heat treatment.Meanwhile,the strip will be annealing embrittlement, the higher the melt temperature of strip, the better toughness,when the tapping temperature exceeding300℃,the soft magnetic properties would violently decline.