Développement d'un composite magnétique doux avec revêtement de ferrite nanométrique

Authors: Lapointe, Philippe
Advisor: Blais, Carl
Abstract: Electric motors, transformers, electromagnets and many other electric devices require materials that can provide a path for magnetic field lines while minimizing losses that they generate. Materials used for these applications are called soft magnetic materials. One way to minimize losses in such materials is to increase their resistivity. In order to do so, highly resistive materials are coupled with ferromagnetic materials. These are called soft magnetic composites. For more than one hundred years, the most common type of soft magnetic composite was made by stacking sheets of rolled iron separated by a thin layer of insulating materials. These were very simple and efficient but also had their share of drawbacks. During the last decades, a new technique based on powder metallurgy was developed. It consists in coating iron particles with an isolating material prior to compaction. This type of materials can be highly resistive. The objective of this project was to develop a soft magnetic composite using metal powders in which the insulating materials would be nanometric NiZn ferrite. Two different techniques were studied in order to achieve this goal. The first one consists in coating iron powders with NiZn ferrite using ferrite plating and the second one consists adding nanoparticles to iron powder. The results obtained throughout this study showed that these two techniques could certainly be used to develop metal powder based soft magnetic composites. More specifically, magnetic weight losses of 11,9 W/kg and 93 W/kg were obtained at 60 Hz and 400 Hz respectively for components prepared using the ferrite plating technique while losses of 13,5 W/kg and 137 W/kg were obtained at 60 Hz and 400 Hz respectively for components prepared by adding ferrite nanoparticles.
Document Type: Mémoire de maîtrise
Issue Date: 2010
Open Access Date: 16 April 2018
Permalink: http://hdl.handle.net/20.500.11794/21343
Grantor: Université Laval
Collection:Thèses et mémoires

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