Crystallization behavior and microstructure of Fe75Co6Zr9B10 alloy

Fe75Co6Zr9B10 amorphous alloy prepared by melt-spinning was annealed at various temperatures. The crystallization behavior and microstructure were investigated by differential thermal analysis (DTA), X-ray diffraction (XRD), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The three exothermal peaks in the DTA curve of Fe75Co6Zr9B10 amorphous alloy correspond to the formations of α-Fe and α-Mn type phases, the growth of BCC-Fe volume fraction at the expense of α-Mn and residual amorphous phase and the precipitations of Fe3Zr, etc. intermetallic compounds, respectively. The second exothermic peak is not influenced by heating rate, but it shifts to a higher temperature region with increasing preannealing temperature of Fe75Co6Zr9B10 alloy. The α-Mn type phase is metastable and its lattice parameter determined by TEM is 0.8830 nm. AFM images show the development of surface morphology of alloy after annealing. The particle size increases with increasing annealing temperature.