Mechanical and magnetic properties of nickel dispersed alumina-based nanocomposite

High-density Al₂O₃/Ni composite with a particular microstructure which ensures superior mechanical and magnetic properties has been developed by hydrogen reduction of NiO to Ni and subsequent hot-pressing of Al₂O₃/nano-sized Ni mixed powder. The nickel nitrate was selected as a starting material of NiO. Microscopic observations revealed that the fine Ni particles - size of about 100 nm - were dispersed homogeneously at the matrix grain boundaries, thus forming intergranular nanocomposite. The composite containing even a small amount of dispersed Ni exhibited considerably high fracture strength. Moreover, the composite has been found to show ferromagnetic properties due to Ni dispersion, which points out the possibility of adding a functional value to structural composites.