Novel Bimorphological Anisotropic Bulk Nanocomposite Materials with High Energy Products

Nanostructuring of magnetically hard and soft materials is fascinating for exploring next‐generation ultrastrong permanent magnets with less expensive rare‐earth elements. However, the resulting hard/soft nanocomposites often exhibit random crystallographic orientations and monomorphological equiaxed grains, leading to inferior magnetic performances compared to corresponding pure rare‐earth magnets. This study describes the first fabrication of a novel bimorphological anisotropic bulk nanocomposite using a multistep deformation approach, which consists of oriented hard‐phase SmCo rod‐shaped grains and soft‐phase Fe(Co) equiaxed grains with a high fraction (≈28 wt%) and small size (≈10 nm). The nanocomposite exhibits a record‐high energy product (28 MGOe) for this class of bulk materials with less rare‐earth elements and outperforms, for the first time, the corresponding pure rare‐earth magnet with 58% enhancement in energy product. These findings open up the door to moving from a pure permanent‐magnet system to a stronger nanocomposite system at lower costs. The fabrication of novel bimorphological anisotropic SmCo7/Fe(Co) bulk nanostructures with a multistep deformation approach is demonstrated. The structures exhibit a record‐high energy product (28 MGOe) for this class of bulk materials with less rare‐earth elements. The resulting nanocomposite outperforms, for the first time, a corresponding pure rare‐earth permanent magnet (SmCo7) with 58% enhancement in energy product.