Mechanical Properties of Aluminum Matrix Composites Reinforced by in Situ Al2o3 Nanoparticles Fabricated Via Direct Chemical Reaction Under Salt Flux

Aluminum matrix reinforced by "in situ" α-Al2O3 nanoparticles are fabricated via a direct chemical reaction between molten aluminum and TiO2 nanopowder under molten salt layer at 700-8000 C under air atmosphere, and the morphologies, sizes and distributions of the in situ particles, as well as the microstructures, mechanical mechanisms of the composites, are investigated by XRD, SEM, Raman spectra and hardness and tensile tests. Aluminum-alumina composites so synthesized have a characteristic metallic lustre and no porosity. The results indicate that the morphologies of the “in situ” particles are mainly cube-shaped, the sizes are in nanometer scale and the distributions in the matrix are uniform.Synthesis of Al-Al2O3 composite system with improved physical properties and structure is held at relatively low temperatures, with the alumina nanoparticles completely wetted by liquid aluminum, which previously did not manage. The microhardness, tensile strength of the composite material is 1.2 times higher than the starting aluminum, and related elongation arises three times after the introduction of nano-α Al2O3 into the aluminum matrix.Composite materials of the Al-Al2O3 system can easily be rolled into thin and ductile foils and wires