Investigations of mechanically alloyed Ni–Zr–Ti–Si amorphous alloys with significant supercooled regions

This study examined the amorphization behavior of Ni57Zr20Ti23−xSix (x=0, 1, 3) alloy powders synthesized by mechanical alloying technique. According to the results, after 5 h of milling, the mechanically alloyed powders were amorphous at compositions of Ni57Zr20Ti23−xSix (x=0, 1, 3). The amorphization behavior of Ni57Zr20Ti20Si3 was examined in details. The conventional X-ray diffraction and synchrotron EXAFS results confirm that the fully amorphous powders formed after 5 h of milling. The thermal stability of the Ni57Zr20Ti23−xSix amorphous powders was investigated by differential scanning calorimeter (DSC). As the results demonstrated, the amorphous powders were found to exhibit a large supercooled liquid region before crystallization. The supercooled liquid regions, defined by the difference between Tg and Tx, (i.e. ΔT=Tg−Tx), are 95 K, 66 K, and 88 K, for Ni57Zr20Ti23, Ni57Zr20Ti22Si1, and Ni57Zr20Ti20Si3, respectively.