Study of Structural and Mechanical Properties of Al/Nano-Al2O3 Metal Matrix Nanocomposite Fabricated by Powder Metallurgy Method

Abstract

In this work, the (1 − x) Al–xAl2O3 (x = 0, 1, 2, 3, and 4 wt%) of metal matrix nanocomposites (MMNCs) has been manufactured using the powder metallurgy technique. Aluminium metal powder (Al) was used as the matrix material, and alumina nanoparticles (Al2O3) synthesized by the sol–gel method were used as the reinforcing material to produce the MMNCs. Two phases of Al2O3 have been identified, i.e. the α-phase (rhombohedral structure) and the δ-phase (orthorhombic structure) by X-ray diffraction patterns (XRD) of synthesized Al2O3 nanoparticles with an average crystallite size of 31.33 nm. The average particle size of the Al2O3 nanoparticle is obtained as 39.6 nm. The XRD patterns of the Al–Al2O3 nanocomposites contain the Al and Al2O3 peaks that confirm the development of the MMNC without any solid-state reaction during the manufacturing process. FESEM micrographs show an almost uniform distribution of Al2O3 particles in the Al metal matrix. The reinforcement of the Al2O3 nanoparticles in the Al metal matrix has shown an improvement in hardness by increasing the wt% of Al2O3 in Al matrix, and a maximum 24.8% improvement in hardness is observed for 4 wt% Al2O3 sample. An increase in wear rate is observed with the increasing wt% of Al2O3 in the Al metal matrix in Al–Al2O3 nanocomposite. The addition of Al2O3 nanoparticles in the Al matrix has resulted in improved corrosion performance of the samples with a maximum corrosion resistance efficiency of 85.6% for 4 wt% Al2O3 in Al metal matrix.