Processing of Cu–Al2O3 metal matrix nanocomposite materials by using high energy ball milling

A Cu-20vol.%Al2O3 nanocomposite material has been successfully produced by using a new approach. This approach involves mechanical alloying of Cu and Al powders to produce Cu–Al alloy powder, mechanical milling of the Cu–Al powder together with CuO powder, and consolidation of the composite powder produced by milling. It has been observed that mechanical alloying of Cu and Al powders with Cu/Al atomic ratio of six leads to formation of a Cu(Al) solid solution. When the Cu(Al) solid solution powder is milled with CuO powder, reaction between Cu(Al) and CuO occurs, extracting Al solute from the Cu(Al) solution and turning it back to pure Cu. It has been identified that the Al2O3 particles in the consolidated composite material have a size smaller than 200 nm in diameter.