Microstructure and mechanical characterization of Cu-Ni/Al2O3 nanocomposites fabricated using a novel in situ reactive synthesis

Chemical-based synthesis of co-formed oxide (CuO-NiO-Al2O3) nanoparticles, followed by selective hydrogen reduction of the Cu and Ni oxides and ultimately consolidation into pellets, produced various compositions of Cu-Ni/Al2O3 nanocomposites. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy analyses were used to characterize the powders. The generated powders ranged in size from 20 to 70 nm, with a considerable presence of agglomerates. According to SEM examination, the powders were homogeneous in shape and particle size. Cold pressed nanocomposite powders were sintered for 2 h at 950 degrees C. SEM with energy dispersive spectroscopy (EDS) was also used to study the microstructure of the sintered specimens. In addition, the physical and mechanical properties of sintered specimens were studied. When the Al2O3 content increased, a more uniform distribution of nanosized Al2O3 particles in the Cu-Ni matrix was attained, resulting in a reduction in particle size. The results also demonstrated that as the Al2O3 concentration was raised, the microhardness and compressive strength of the nanocomposites rose by 74% and 67% compared to pure alloy, with the exception of fracture strain, which decreased dramatically.