Electrodeposition and mechanical properties of Ni-Al2O3 nanocomposites

The jet electrodeposition technology was used to prepare nano-Al2O3 nanocomposites. Effect of the additive amount of nano-Al2O3 particles and cathode current density on the nanoparticle content in composites was studied. The scanning electron microscope and X-ray diffractometer were adopted to analyze the micromorphology of the composites, research the effect of nanoparticle content in composites on the microhardness, bonding strength, and corrosion resistance. The results show that nickel deposited layer has the nanocrystalline microstructure, with the average grain size of about 40 nm; the content of nano-Al2O3 particles in the deposited layer can reach 2.5 wt%; the composite coating prepared are all face-centered cubic structure and represent a (200) preferential orientation. With the increase of Al2O3 content, the microhardness of coating will increase gradually and the bonding strength and corrosion resistance will first increase and then decrease.