Browsing by Author "Gokelma, Mertol"

Filter results by typing the first few letters
Now showing 1 - 1 of 1
  • Thumbnail Image
    Article
    A Critical Analysis of Pulverization Mechanism During Hydrogen Decrepitation of End-Of Ndfeb Magnets
    (Elsevier Science Sa, 2025) Habibzadeh, Alireza; Gokelma, Mertol; 01. Izmir Institute of Technology; 03. Faculty of Engineering; 03.09. Department of Materials Science and Engineering
    Given the increasing demand and limited availability of rare earth elements (REEs), innovative solutions are critical to managing supply risks. Recycling is a key strategy in mitigating these risks, particularly for NdFeB magnets, which consume a large portion of REEs. Among the various recycling processes, hydrogen decrepitation (HD) has gained popularity due to its efficiency in producing fine powders for magnet-to-magnet recycling. While the HD mechanism is commonly attributed to hydride formation in the Nd-rich grain boundary phase, this study presents new findings that challenge this assumption. Through the hydrogenation of End-of-Life (EoL) NdFeB magnets at temperatures ranging from 25 to 400 & ring;C, the results indicate that the primary mechanism of pulverization arises from hydride formation in the Nd2Fe14B matrix rather than in the Nd-rich phase, especially at low temperatures where NdH2 formation is kinetically unfavorable. This revised mechanism was supported by evidence from X-ray diffraction, BSE and SE-SEM imaging, particle size analysis, diffusion modeling, and stress analysis.