Synthesis and mechanical properties of aluminum alloy 5083/SiCnp nanocomposites

Abstract

Aluminum-based nanocomposites have been gaining significant attention due to their light weights, machinability, low coefficient of thermal expansions and high strengths. For these advantages, aluminum-based nanocomposites are widely used in marine and automobile industries. In this study, nanostructured Al5083-based nanocomposites with different percentages of SiC nanoparticles (SiCnp) were synthesized using mechanical milling route, and their mechanical behaviors were examined in compression, shear punch and microhardness. Optical and electron microscopies were used to investigate microstructures, as well as nanoparticle distributions in the nanocomposites. Crystallite size and residual lattice strain were measured in the two forms of powder and bulk samples by X-ray diffraction method. Results showed that the crystallite size of the nanocomposite sample containing 5 wt% SiCnp decreased 22%, compared to that containing 1 wt% SiCnp. Similarly, by increasing the reinforcement percentage, a reduction in the grain size was observed in the microstructure of the nanocomposite samples. Also, when the reinforcement contents were increased, both porosity and microhardness of the nanocomposites increased. Compared with the unreinforced alloy, results showed that the compressive and shear yield strengths of the nanocomposite containing 5% wt. reinforcement improved 95% and 83%, respectively.