KAPLAN, CansuKAPLAN, GizemÇAKIR, Öznur2026-01-282026-01-282026-01-15https://kurumsalarsiv.tenmak.gov.tr/handle/20.500.12878/2091Demand for rare earth elements (REEs) in NdFeB permanent magnets used in wind energy and EV necessitates efficient recycling to address supply chain vulnerabilities and environmental concerns. Hydrogen decrepitation (HD), hydrogen-assisted decrepitation process, offers a promising method for processing end-of-life Hard Disk Drive (HDD) NdFeB magnets by converting them into demagnetised powders while preserving microstructural integrity. This study investigates the impact on hydrogenation temperature (room temperature, 50°C, 75°C) on the recycling process at 4 bar hydrogen pressure and 2 hours. Chemical composition was determined by ICP-OES, oxygen and hydrogen contents by LECO analysis, phase identification by XRD with Rietveld refinement, and microstructure by SEMEDS. Results indicate that reduced temperatures promote hydrogen absorption, diminish oxidation, and produce finer particles characterised by typical intergranular fractures. XRD confirmed the formation of Nd₂Fe₁₄BHₓ phases with decreasing hydrogen content at elevated temperatures, along with an increased presence of Nd₂O₃ due to the exposure of reactive surfaces. According to these results, HD at room temperature under 4 bar is optimal for the effective and sustainable recycling of NdFeB magnets, eliminating the need for further heat treatment.enHydrogen DecrepitationNdFeB MagnetsconferenceObject