Mechanochemical reactions in nanocrystalline Cu–Fe system induced by mechanical alloying in air atmosphere

Metastable nanocrystalline FCC and BCC Fe–Cu solid solutions were synthesized from elemental powders using a high-energy ball mill in air atmosphere. The structural and morphological changes during mechanical milling were investigated by X-ray diffraction and scanning electron microscopy. The patterns so obtained were analyzed using the XʹPert High Score Plus program. The final product of the mechanical alloying process was nanocrystalline double-phase FCC Cu(Fe) and BCC Fe(Cu) solid solutions with a mean crystallite size in the range of a few nanometers. Moreover, the mechanical alloying of Fe–Cu, in air atmosphere, resulted in partial oxidation to Cu2O and CuO. Prolonged milling supported the formation of CuO oxide and the interdiffusion between FCC–Cu(Fe), BCC–Fe(Cu) and cupric oxide (CuO). Scanning electron microscopy results showed that flattened Fe–Cu powders were laid and welded on each other and tended to form a matrix of randomly welded thin layers of highly deformed particles.