Processing of nanocrystalline copper by mechanochemical reduction of CuO and Cu 2 O with graphite

Abstract

The preparation of nanocrystalline Cu by mechanochemical reaction of carbon with copper oxides, CuO and Cu₂O, has been studied. The phase and structural transformations, crystallite size, lattice micro strain and lattice parameters were characterised using X-ray diffraction (XRD). Morphology of the synthesis products was evaluated by scanning electron microscopy (SEM). It was found that the reduction process of CuO to Cu takes place in two steps, while Cu was produced directly through one step from Cu₂O. In addition, kinetics of nucleation and formation of Cu through solid state reduction of CuO is different from the reduction of Cu₂O. The results reveal that the average crystallite size of copper derived from CuO after 100 h milling is ∼18 nm, while for copper derived from Cu₂O after 30 h is ∼27 nm. A trivial solid solubility of C in Cu was achieved by mechanical alloying.