Enhancement of magnetic and microstructural properties in Fe-Cr-Co-Mo-V-Zr-Y permanent magnetic alloy

Abstract

Abstract The 43-xFe-28Cr-23Co-3Mo-2V-1Zr-xY; x = 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 wt% permanent magnets were produced through casting, thermomagnetic annealing and aging treatments. Magnetic and microstructural properties were improved by Y addition and process optimization. The Y element modifies the morphology of ferromagnetic F-Co rich phase, introduces filed anisotropy and contributes in coercivity enhancement. XRD and EDS results showed that Y free 43Fe-28Cr-23Co-3Mo-2V-1Zr alloy is composed of Fe-Co-V (54.4%) and Cr-Mo-Zr (45.6%) phases while Y doped 41Fe-28Cr-23Co-3Mo-2V-1Zr-2Y alloy is consists of Fe-Co-V-Y (55.7%), Cr-Mo-Zr (29.3%) and Y1Co5 (15%) magnetic phases. Micrographs obtained by scanning transmission electron microscope elucidate nanostructural exchange coupled Fe-Co-V-Y (15–20 nm), Cr-Mo-Zr and Y1Co5 (10 nm) phases for 41Fe-28Cr-23Co-3Mo-2V-1Zr-2Y alloy. Pole figures and ODFs deduced sharp magnetic {1 1 0}〈0 0 1〉 textures or preferential orientation of Fe-Co rich rod like particles. Henkel plots deduced strong ferromagnetic exchange interactions between the magnetic phases. The 43Fe-28Cr-23Co-3Mo-2V-1Zr alloy yields Br of 0.71 T, Hc of 97 kA/m and (BH)max of 51.3 kJ/m3 which were remarkably improved to Br of 1.05 T, Hc of 130 kA/m and (BH)max of 61.6 kJ/m3 with 41Fe-28Cr-23Co-3Mo-2V-1Zr-2Y alloy.