20.500.12556/DiRROS-21790 Effects of thermal demagnetization in air on the microstructure and organic contamination of NdFeB magnets Demagnetization is an essential step for the demounting and safe handling of end-of-life NdFeB. Thermal demagnetization in air is a straightforward option to demount adhesive-fixed or segmented magnets. However, this process is suspected to increase the uptake of contaminants like O, C and Zn from coatings and adhesives, potentially degrading the recyclate quality. This study tests the effects of thermal demagnetization in air at 400 °C for 15 to 240 min on variously coated samples with different initial oxidation levels. Furthermore, the possible reversal of the contaminant uptake is explored. Samples with low previous oxidation levels showed significant uptake in oxygen with a minimal diffusion depth, while the uptake depended on the used coating. The best protectiveness was achieved with NiCuNi with an increase in oxygen of only around 30%. Epoxy (up to ~130% O uptake) and Zn coatings (up to ~80% O uptake) disintegrated during the treatment and offered less protection but still made a difference compared to uncoated samples (up to ~220% O uptake). Samples with high initial oxidation levels show no clear tendency towards further oxygen uptake and the carbon uptake is generally low, likely due to contemporary epoxy coatings featuring a passivation underneath as a barrier layer. Zn infiltration, which carried organic debris, was observed. Short demagnetization times proved to be favorable for limiting the depth of the diffusing contaminants. Mechanical coating removal after thermal demagnetization in air can mitigate the contaminant uptake, producing clean, recyclable end-of-life material. magnetic scrap thermal demagnetization organic contamination razmagnetenje true false true MDPI Švica Angleški jezik Slovenski jezik © 2024 by the authors. Neznano 2025-03-28 12:49:30 2025-03-28 12:49:30 2025-10-24 03:49:50 0000-00-00 00:00:00 2024 0 0 Nasl. z nasl. zaslona; Soavtorja iz Slovenije: Tomaž Tomše, Spomenka Kobe; Opis vira z dne 14. 11. 2024; str. 1-12 iss. 22, [article no.] 5528 Vol. 17 Nov. 2024 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2024-10-15 2024-11-11 2024-11-13 621.7+621.9 1996-1944 10.3390/ma17225528 214969859 https://www.mdpi.com/1996-1944/17/22/5528 1 b75a9415-0bca-11f0-963a-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=31404 RAZ_Grau_Laura_2024.pdf RAZ_Grau_Laura_2024.pdf 1 5BE352FCBA5258F2EA85080F9682F0C2 c4e274ab039040421a01e5764ca5710ff784f7af79e1e39ad5be954edfa0b970 7d75245f-0bcb-11f0-963a-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=31405 Institut Jožef Stefan 0 0 0