Phase formation in mechanically alloyed Nb-Al powders

The mechanical alloying route to synthesize Nb sub(3)Al intermetallic compound formed from blended elemental powders was studied. The effects of a process control agent (PCA) on the structural change during mechanical alloying were also studied. X ray diffraction analysis of the mechanically alloyed powder revealed the complete overlapping of Al(111) and Nb(110) reflections. After milling, the peaks disappeared and only the Nb-based solid solution was left. The powder became amorphous after milling for 16 hours. In the case of the milling using hexane as the PCA, the time to amorphization decreased with the addition of hexane and the decrease in the crystalline size and the increase in internal strain were more drastic.