Preparation and thermal stability of mechanically alloyed Ni-Zr-Ti-Y amorphous powders

In the current study, amorphous Ni67-xZr10Ti 23Yx alloy powders were synthesized by mechanical alloying technique. The mechanically alloyed powders were amorphous, after 5 h of milling, at compositions of Ni67-xZr10Ti 23Yx (x=0-12). The amorphization behavior of Ni 59Zr10Ti23Y8 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 Ni67-xZr10Ti23Y x amorphous powders was investigated by differential scanning calorimeter. As the results demonstrated, the amorphous powders with low yttrium concentration (x=0-6) or high yttrium concentration (x=12) exhibit no glass transition behavior. However, the Ni67-xZr10Ti 23Yx (x=7-10) amorphous powders were found to exhibit a wide supercooled liquid region before crystallization.