Structure and crystallization of amorphous Cu–Zr–Al powders

In this work, the structure and crystallization of amorphous (Cu50Zr50)100 − xAlx, (x = 0, 2.5, 5, 7.5, 10) powders produced by gas atomization were studied. X-ray diffraction patterns showed an amorphous structure in the as-atomized powders; however, TEM observations revealed the presence of nanocrystals in all the samples. Differential Scanning Calorimetry (DSC) analyses revealed an improved glass forming ability (GFA) in the alloys containing Al, with the (Cu50Zr50)97.5Al2.5 alloy being the one with the best GFA. Kissinger analyses showed that the activation energy Ea for crystallization increased with the Al content, and the Avrami parameter, n was higher compared to traditional crystalline metallic alloys. Structural analyses of crystallized samples revealed the formation of Cu10Zr7 nanocrystals.