Effects of temperature and pressure on decrepitation behavior of Ho-containing NdFeB magnets
Journal of Alloys and Compounds, cilt.1077, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 1077
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.jallcom.2026.189479
- Dergi Adı: Journal of Alloys and Compounds
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC, Public Affairs Index, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: Holmium, Hydrogen Decrepitation, Hydrogenation, Rare Earth Elements
- Yıldız Teknik Üniversitesi Adresli: Evet
Özet
NdFeB magnets are widely used in various applications; however, effective pre-treatment of end-of-life (EoL) magnets for recycling through hydrogen processing remains challenging. In particular, limited information is available regarding the combined effects of temperature and pressure on the properties of hydrogenation products. In this work, two types of NdFeB magnets were hydrogen decrepitated (HD) under varying temperatures (25–100 °C) and hydrogen pressures (1–15 bar). The results showed that, for the low-Ho-containing magnet, the smallest D50 value of 32.61 µm can be achieved at 25 °C and 10 bar H2. Increasing the temperature and further increasing the pressure deteriorated the decrepitation efficiency. The presence of Ho in the structure negatively affected the retained hydrogen content (0.646 wt% vs. 0.712 wt% for the low-Ho-containing magnet) and the decrepitation efficiency, which can be associated with the reduced unit cell volume and differences in hydrogen accommodation behavior. Furthermore, different matrix hydride phases were identified, with Nd2Fe14BH1.86 dominating in the high-Ho-containing (6.52 wt%) magnet compared to Nd2Fe14BH3.31 in the low-Ho-containing (0.10 wt%) counterpart. These findings provide new insights into the combined effects of processing parameters and composition on the HD process and contribute to the optimization of low-temperature hydrogen-based recycling of NdFeB magnets.