Microstructures of Co-Zr-B alloys produced by melt-spinning technique

Abstract

The microstructures of high-coercivity Co-Zr-B melt-spun ribbons were examined in order to determine the hard magnetic phase in the Co-Zr-B alloys. Throughout X-ray diffraction (XRD) and magnetic studies, as well as microstructural studies by scanning electron microscope (SEM), transmission electron microscope (TEM), and scanning transmission electron microscope (STEM), no Co5Zr phase was found in the Co-Zr-B melt-spun ribbons. Only the CoxZr (x ≈ 5) phase was detected, indicating that the hard magnetic phase in the Co-Zr-B alloys was the CoxZr phase. The TEM and STEM studies revealed that the Co-Zr-B alloys had very fine CoxZr grains of around 200 nm in diameter and that the hard magnetic CoxZr phase was surrounded by the soft magnetic Co grain boundary phase. © 2013 Elsevier B.V. All rights reserved.