Study On Optimizing Process Of Loss Performance Of Fe-6.5wt%Si Magnetic Powder Core

Magnetic powder core is a kind of soft magnetic material with magnetoelectric conversion function,which can meet the current needs of electronic and electrical equipment for large-capacity and miniaturization.So far,a variety of magnetic powder cores have been developed,including iron silicon,sendust magnetic powder cores,etc.Among them,Fe-6.5wt%Si magnetic powder cores have excellent DC bias characteristics,low loss performance at high frequencies,and low cost,is widely used in electronic devices,and to measure the quality of magnetic powder cores,the loss caused by the energy conversion process is an important performance index.The loss of magnetic powder core is composed of hysteresis loss,eddy current loss and residual loss.How to reduce the loss of magnetic powder core is a major problem under the premise of maintaining good magnetic permeability.Aiming at this problem,this paper selects Fe-6.5wt%Si magnetic powder core as the experimental research object.Starting from the purpose of reducing the loss of magnetic powder core,high-temperature heat treatment processes are used to reduce the hysteresis loss of magnetic powder core,and try to use organic-inorganic double Layer insulation coating process to reduce the eddy current loss of the magnetic powder core.At the same time,combined with scanning electron microscopy,XRD and other characterization methods to analyze the phase composition and microstructure of the powder and iron core,try to change the parameters of the insulating agent,pressing pressure and annealing temperature in the magnetic powder core preparation process,and combine with experimental equipment such as magnetic performance testing equipment,To study the influence of parameter changes on the magnetic properties of magnetic powder cores.The specific research results are as follows.1.In the experiment of exploring the influence of Fe-6.5wt%Si powder high temperature heat treatment process on the performance of magnetic powder core,it is found that the Fe(110)peak of Fe-6.5wt%Si powder after annealing treatment has different amplitudes towards high angles.Offset phenomenon;the saturation magnetic induction intensity of the powder gradually decreases with the increase of temperature,and the coercive force first increases and then decreases;the content of carbon and oxygen impurity elements in the powder gradually decreases with the increase of temperature.Fe-6.5wt%Si magnetic powder core made of different annealed powders,the magnetic permeability gradually decreases from 500?to900?,and the value is basically maintained at about 80(100m T?50KHz),up to 90(the powder after 500?processing);the total loss of the magnetic powder core is greatly reduced with the significant reduction of the hysteresis loss,and gradually decreases at the annealing temperature of 500?to 900?,from 830 m W/cm³ to630 m W/cm³(100m T?50KHz).In the experiment to explore the effect of annealing temperature of Fe-6.5wt%Si magnetic powder core on performance,it is found that the magnetic powder core made of powder without heat treatment increases with the increase of temperature,and the resistivity and coercivity are somewhat increased.Decrease;the magnetic permeability of the magnetic powder core gradually increases at a temperature of 500?800?,the highest value is 127,and it decreases at900?;the total loss of the magnetic powder core gradually decreases at a temperature of 500?900?,and the lowest value is 649 m W/cm³.On the basis of the above process,after carrying out the double annealing experiment,it is found that the magnetic performance of the magnetic powder core made of the powder particles heat-treated at 900? is better than that of the magnetic powder core made at 500?,and the magnetic permeability is maintained at 80%.Around,the magnetic loss is lower between(600?700)m W/cm³,and the lowest value is 625 m W/cm³.2.In the exploration of the performance optimization experiment of the organic-inorganic double-layer insulation coating process on the Fe-6.5wt%Si magnetic powder core,it was found that under the condition of the highest pressure of 1600MPa in this test,the Fe-6.5wt%Si magnetic powder core The medium Si O₂inorganic layer has not been damaged,and the double-coated Fe-6.5wt%Si magnetic powder core maintains good insulation performance.Compared with the magnetic permeability of the single-layer coated magnetic powder core,the double-layer coated magnetic powder core magnetic The conductivity has only dropped by 3(100m T?50KHz)units,and the total loss has been effectively reduced,from 1215m W/cm³ to 905 m W/cm³(100m T?50KHz).3.In the experiment of optimizing the organic-inorganic double-layer insulation coating process parameters,it is found that with the increase of the insulating resin content,the coating layer of the composite powder gradually increases,the saturation magnetic induction intensity of the powder gradually decreases,and the density and effectiveness of the magnetic powder core The magnetic permeability first increases and then decreases;with the addition of 1.5wt%organic resin,the powder has the best insulation coating,the resulting magnetic powder core has the lowest loss,905m W/cm³,and the highest magnetic permeability,49(100m T?50KHz).The molding pressure has a positive effect on the performance improvement of the magnetic powder core.With the increase of pressure,the loss of the magnetic powder core is gradually reduced without destroying the double coating layer,the minimum is 880m W/cm³,and the magnetic permeability gradually increased,the highest is 53.4.Constrained by the heat resistance of the insulating resin,the magnetic permeability of the magnetic powder core is increased between 400 and 700?,and the total loss gradually decreases,and it deteriorates sharply at 800?.