Effect of Si and Co on the crystallization of Al–Ni–RE amorphous alloys

Crystallization of Al83Ni10Si2Ce5, Al85Ni10Ce5, Al87Ni7Nd6 and Al87Ni5Co2Nd6 amorphous alloys has been studied by using X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The multiple transition metal (TM) (containing metalloid element) have significant effect on the crystallization behavior. A small addition of Si transforms a eutectic crystallization (Al85Ni10Ce5) to a primary crystallization (Al83Ni10Si2Ce5); while a small addition of Co transforms a primary crystallization (Al87Ni7Nd6) to a eutectic crystallization (Al87Ni5Co2Nd6). In addition, the activation energies for crystallization (Ea) are obtained to be 191, 290, 221 and 166 kJ/mol for the Al83Ni10Si2Ce5, Al85Ni10Ce5, Al87Ni5Co2Nd6 and Al87Ni7Nd6 amorphous alloys based on the Kissinger method, respectively. It is found that the primary crystallization of fcc-Al is characteristic of a lower Ea, as compared with eutectic crystallization.