Non-isothermal kinetics study of primary crystallization in amorphous Al86Ni10Zr2MM2 alloy

The non-isothermal kinetics of crystallization in amorphous Al86Ni10Zr2MM2 (MM: misch metal) alloy have been studied utilizing differential scanning calorimetry (DSC), transmission electron microscopy (TEM) and X-ray diffraction (XRD). Non-isothermal DSC experiment showed that the crystallization process of the Al86Ni10Zr2MM2 alloy take place in three steps. The first crystallization step is corresponding to the precipitation of fcc-Al nanoparticles. The XRD results showed that partially overlapped second and third peaks are related to precipitation of Al11MM3, Al3Ni and Al3Zr phases. Utilizing Kissinger method, the mean value of activation energy has been evaluated for all crystallization steps. The results showed that the crystallization activation energy for first, second and third crystallization step are 251.6±6.2, 270.4±7.1 and 289.6±3.9kJ/mol respectively. The obtained mean value of the Avrami exponent for first crystallization stage revealed that the crystallization mechanism was a decreasing nucleation rate crystallization process in diffusion control regime.