Sintered magnets based on rare earths (NdFeB) have become practically indispensable in today's era due to rapid technological development. Their main disadvantage is that they corrode very quickly, which is accelerated by exposure to elevated temperatures or corrosive medium. Corrosion protection is therefore necessary and the main factor for achieving the desired lifetime of the magnet. The aim of the thesis was to examine which anti-corrosion protections would still be technically acceptable for aggressive wet applications, in our case specifically for use on a rotor that would work in gear oil WF074-030, manufactured by Fuchs. We also considered affordable solutions and thus tested six different coatings, four metallic (NiCuNi in two versions, matted and unmatted, CuNiNi, and ZnAl) and two non-metallic (passivation and Everlube (hybrid coating)). We performed basic analyses, such as measurement of microhardness, coating thickness, roughness measurements before and after corrosion tests, such as the PCT test and the test in gear oil. In addition, after the exposure tests, microscopic analyzes of the surface and cross-section of the samples were performed. We have come to the conclusion that the most suitable protections are CuNiNi and unmatted NiCuNi.
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