Crystallization Behavior of Fe_50?xCr₁₅Mo₁₄C₁₅B₆M_x (x=0, 2 and M = Y, Gd) Bulk Metallic Glasses and Ribbons by in situ High Temperature X-Ray Diffraction

The effect of rare earth addition on thermal stability of Fe_50?xCr₁₅Mo₁₄C₁₅B₆M_x (x=0, 2 and M=Y, Gd) is studied. Thermal and structural properties are measured using differential scanning calorimetry and x-ray diffraction, respectively. The microstructure is observed by using a scanning electron microscope, and chemical composition is checked by energy dispersive spectroscopy analysis. The effect of high temperature on the isothermal crystallization of Fe_50?xCr₁₅Mo₁₄C₁₅B₆M_x (x=0, 2 and M=Y, Gd) bulk metallic glass and ribbons is investigated by high-temperature x-ray diffraction. It is found that the crystallization behavior of Fe_50?xCr₁₅Mo₁₄C₁₅B₆M_x(x=0, 2 and M=Y, Gd) bulk metallic glass strongly depends on the annealing temperature. The different crystallization behavior is believed to be due to the different structures that the metallic glass possesses at different temperatures.