Influence of the ingot solidification microstructure on the formation kinetics of icosahedral quasicrystalline phase during the crystallization of the corresponding amorphous alloy

Abstract

Zr65Al7.5Cu12.5Ni10Ag5 ingots with different solidification microstructures are obtained by repeated arc melting of origin ingots. Under the same conditions, slices of amorphous alloys can be produced by suction casting in a copper mold. Differential scanning calorimetry (DSC) is employed to investigate the crystallization kinetics of the amorphous alloys. X-ray diffraction patterns (XRD) show that icosahedral quasicrystalline phase (I-phase) precipitates as primary phase during the crystallization of Zr65Al7.5Cu12.5Ni10Ag5 amorphous alloys. The results of Kissinger analyses suggest that the amorphous alloys made from the ingot with finer microstructure show better thermal stability, and that the I-phase precipitated becomes more stable against decomposition. Within the frame of structure heredity, the influence of ingot microstructure on the formation kinetics of I-phase during the crystallization of corresponding amorphous alloys is discussed.