Phase transformation of the CuAl2 intermetallic alloy during high-energy ball-milling

In the present investigation, we have studied the phase transformation of the CuAl2 intermetallic alloy with tetragonal structure by high-energy ball-milling. The structural changes with milling time were followed by X-ray diffraction, differential scanning calorimetry and electron microscopy. It is found that CuAl2-phase transforms to body centered cubic structure after a long periods of high-energy ball-milling time. According to SEM results, the milling powders change their mechanical behavior from brittle to ductile during the phase transformation. Rietveld analysis showed that around 29% of unit cells in the metastable cubic structure are occupied by Cu suggesting Al segregation in the material and explaining the change in the mechanical behavior of the alloy.