Magnetic induction of polymer composites filled with ferrite powders

摘要

Purpose: The goal of this work was to determine influence of amount and type of ferrite fillers on magnetic induction of epoxy composites. Six mixtures that contain different amount of ferrite powder were prepared. Additionally an effect of type and amount of introduced ferrite powder on epoxy resin processing conditions and parameters was searched. Design/methodology/approach: In this research the method of preparing polymeric gradient composites was centrifugal casting. The experimental procedure focused on evaluating the magnetic induction of gradient composites. Magnetic induction of composites based on epoxy resin, which contain ferrite powders was measured using milliteslometer. Measurements were performed for three filler contents and for two types of filler. Findings: Centrifugal casting method allowed obtaining materials with different percentage of ferrite content in subsequent layers of cylindrical composites. Moreover it was observed that values of magnetic induction were higher for composite with barium ferrite than for composite with strontium ferrite but the difference was not too high. Research limitations/implications: The main problem of this work was about limitation of maximum level of fillers content. Adding more filler than 30%vol caused very rapid composite viscosity increase and made air removing and casting impossible. For that reason there were made composites with 10%vol., 20%vol. and 30%vol. of ferrite powders. Trials were performed with mixtures that contained up to 50%vol. of filler. Practical implications: Method applied in this research allowed to obtain materials that are characterized by gradient of magnetic properties. Such composites find applications in electrotechnical industry and in mechanical engineering. Originality/value: New polymeric gradient materials were developed using centrifugal casting technology. Magnetic properties of these composites were determined depending on distance from the surface of the test piece.