Fabrication of bulk anisotropic Nd2Fe14B/α-Fe nanocomposite magnets with two-step high-pressure thermal compression

For bulk Nd2Fe14B/α-Fe nanocomposite magnets, it is a challenge to induce the crystallographic texture of Nd2Fe14B nanocrystals on the premise of keeping a high fraction of α-Fe phase (>30 wt%) combined with a small grain size (∼10 nm). Here, we fabricated a bulk anisotropic Nd2Fe14B/α-Fe nanocomposite with a strong (00l) texture for Nd2Fe14B nanocrystals and a high fraction (∼31 wt%) and small size (∼19 nm) for α-Fe grains, using two-step high-pressure thermal compression that facilitates the alignment of the (00l) axes of the Nd2Fe14B nanocrystals. The deformed magnet exhibits a superior energy product of 24.3 MGOe compared with the typical values of the bulk Nd2Fe14B-type nanocomposites with soft-phase fractions above 20 wt%. This study provides a promising strategy to prepare bulk anisotropic nanocomposite magnets with high energy products.