Mechanical Properties of Aluminum-Matrix-Nanoparticle Composites

Aluminum-matrix-nanoparticle composites were produced by ball milling of micro scale aluminum powder with different additions of 500 nm mean diameter SiC particles in air atmosphere with subsequent consolidation by hot extrusion. The material was investigated in this condition by tensile testing, hot tensile testing, density, hardness, and amplitude dependent damping measurements. The amplitude dependent damping of the material was investigated after slow furnace heating and cooling as after quenching into water to the room temperature. The results of the tensile and hot tensile testing show that the addition of SiC particles lead to a significant increase of tensile strength, but the remaining porosity increased, too. The results obtained for the amplitude dependent damping can be attributed to cracks present in the consolidated material or cracks produced by thermal stresses.