Investigation of hardness and electrical conductivity of Cu-CaO nanocomposite produced by mechanochemical method

The Cu-CaO nanocomposite was successfully synthesized by reactive milling of Cu۲O and Ca powders. The products were characterized by X-ray diffraction and scanning electron microscopy. The microstructure and morphology of produced samples were evaluated and the effects of process parameters on the Cu-CaO nanocomposite was studied. Results indicate that reaction begins after ۵ hours. Moreover, the size of Ca and Cu۲O crystallite after ۱۷ hours milling has been ۱۷ and ۲۴ nm. In the following, for production۱ samples with Cu-۱%CaO, Cu-۳%CaO, Cu-۵%CaO and Cu-۷%CaO composition, pure copper was added to composite powder which was produced in mechanochemical process and the resulting powders were milled for ۱۵ hours. To investigate the properties of resulted composite, this powder was compacted and sintered for ۹۰ minutes in ۶۰۰, ۷۰۰ and ۸۰۰ °C. The images of scanning electron microscope equipped by X-ray map and optical microscope show the growth of copper grains and also the presence of CaO particles with dimensions of less than ۱۰۰ nm. Moreover, the results indicate that by increasing the temperature of sintering, the hardness and electrical conductivity increase, but by increasing reinforcing phase the conductivity decreases and hardness increases.

کلیدواژه ها:

Nanocomposite ، mechanochemical process ، hardness ، electrical conductivity