Jet Electrodeposited Cu-Al₂O₃ Nanocomposite Coatings

A jet electrodeposition device was carried out to prepare Cu-Al₂O₃ nanocomposite coatings. The influence of the concentration of Al₂O₃ in the electrolyte and parameters, such as cathodic current density, the electrolyte temperature as well as the electrolyte jet velocity, on the content of the Al₂O₃ in the deposite were investigated. The coatings ingredient and microstructure was measured by the scanning electron microscope (SEM) with energy dispersive analyzer system (EDX), the microhardness tests were conducted on an microhardness tester. The results show that the jet electrodeposition can fine crystalline particles. The copper deposited layers have nanocrystalline microstructure with grain size of about 50nm. The amount of Al₂O₃ in composites first increased and then decreased with an increase in the concentration of Al₂O₃, current density, temperature and jet velocity. The composite with optimum atomic percent of Al₂O₃ (14.4 at%) can be obtained at the concentration of 30 g/l, cathodic current densities 300 A/dm², temperature 30°C, and electrolyte jet velocity 8 m/s. The addition of Al₂O₃ in copper increases the microhardness of the electrodeposited coatings.