Mechanical and corrosion behaviours of Al/SiC and Al/Al 2 O 3 metal matrix nanocomposites fabricated using powder metallurgy route

Abstract

In the current investigation, several Al/SiC and Al/Al₂O₃ metal matrix nanocomposites (MMNCs) were fabricated using the powder metallurgy route. The microstructure and the mechanical properties of the fabricated MMNCs were evaluated. Moreover, the corrosion behaviour of the MMNCs in NaCl aqueous solution under several corrosion test conditions of NaCl concentration, solution temperature and exposure durations was investigated. The corrosion tests were designed using Taguchi's design of experiments approach. Mathematical correlations were obtained to predict the corrosion rates of the MMNCs as a function of the corrosion test parameters. The results revealed that both Al/Al₂O₃ and Al/SiC MMNCs exhibited higher hardness than the pure Al matrix. The increase in the volume fraction and/or the size of the nanoparticles results in an increase in the hardness of MMNCs. Both Al/SiC and Al/Al₂O₃ MMNCs showed better corrosion resistance than the pure Al matrix in NaCl aqueous solution. However, the Al/Al₂O₃ MMNCs exhibited lower corrosion rates than the Al/SiC MMNCs. It has been found that the NaCl solution temperature and the exposure time showed the highest and lowest statistical physical significance on the corrosion rate of MMNCs respectively.