A sustainable route to high-performance Nd-Fe-B magnets using recycled feedstock and grain boundary design
Year: 2025
Type: article
Abstract: Advanced grain boundary engineering through Zr-based additives has enabled a breakthrough in recycled Nd-Fe-B permanent magnet performance, achieving an exceptional intrinsic coercivity (Hcj) of 1930 kA/m at 20°C—surpassing virgin magnet benchmarks. The enhanced magnetic architecture stems from the controlled formation of nanoscale ZrB2 precipitates, which exhibit preferential growth along (001) planes, creating an optimized network of grain boundaries. Detailed microstructural characterization revealed various distinct intergranular phases, including Fe-Nd oxides and Co-Cu-rich regions, working synergistically to enhance magnetic isolation and structural stability. In this study, we distinguish between grain boundary (GB) regions, which separate Nd2Fe14B grains and serve as diffusion pathways, and intergranular (IG) phases, which form at grain junctions and play a role in magnetic isolation.The engineered grain boundary network, verified through comprehensive TEM and EDXS analyses, facilitates superior thermal stability with improved reversible temperature coefficients across operational temperature ranges. This validated recycling approach not only preserves but enhances critical magnetic properties, establishing a scalable pathway for producing high-performance magnets that meet the demanding requirements of electric mobility and renewable energy applications while addressing rare earth supply chain vulnerabilities.
Source: Results in Materials
Institution: Jožef Stefan Institute
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,530
OpenAlex ID: W4415328288