الفهرس 
Chapter 1: IntroductionOnly 14 pages are availabe for public view
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Abstract
in the current study, Cu-Ni/Al2O3 nanocomposites with 3, 5, and 8% Al2O3 wt%. concentrations are synthetics. Thermochemical technique by thermal decomposition of Cu, Ni, and Al nitrate solutions is utilized and followed by selective hydrogen reduction of the resulting Cu and Ni oxides. Finally, nanostructured Cu-Ni/Al2O3 nanocomposites with better mechanical and thermal properties are obtained by pressure consolidation and sintering. The crystallite size and structure of Cu-Ni/Al2O3 nanocomposites are investigated using (XRD). The surface morphologies of Cu-Ni/Al2O3 nanocomposites are analyzed using (FE-SEM). Cu-Ni/Al2O3 nanocomposites are investigated for their physical, mechanical, thermal, electrical, and tribological properties.
The findings revealed that Al2O3 nanoparticles (average 20 nm) are dispersed uniformly throughout the copper-nickel matrix. The relative density, the electrical and thermal conductivities, and thermal expansion coefficient are reduced as the amount of Al2O3 in the Cu-Ni matrix increases. The results also demonstrate that as the Al2O3 concentration is raised, the microhardness and compressive strength of the nanocomposites rose by 74% and 67% compared to pure matrix, except for fracture strain, which decreases dramatically. The sliding wear rate and coefficient of friction of the Cu-Ni/Al2O3 nanocomposites enhance with the increasing load at constant sliding velocity and are always lower than that of Cu-Ni at any load, achieving a 67% decrease in wear rate for Cu-Ni/8%Al2O3 nanocomposite compared to the Cu-Ni matrix. Due to the enhanced properties shown by the developed Cu-Ni/Al2O3, it can be considered a promising alternative material for various applications involving increased wear resistance and hardness.