Mechanical properties of a new kind of porous aluminum alloy composite from ceramic hollow spheres with high strength

Abstract

A new kind of porous 6061 aluminum alloy composite material was successfully fabricated using self-made high-strength silicon-containing ceramic hollow spheres as reinforcement. For comparison, another composite with commercial alumina hollow spheres was produced. All of these porous composite materials were produced by sintering at 650 ℃ for 2 h. Their microstructures display that the aluminum alloy reacts with the self-made ceramic hollow spheres, forming a thin transition layer containing MgO and Al2O3. Moreover, it was analyzed that the influence of the different classes of ceramic hollow spheres on the properties of porous composites, including the compressive strength, specific strength and energy absorption performance. The results indicate that the self-made silicon-containing ceramic hollow sphere can help to hinder the plastic deformation of the aluminum alloy metal matrix, which makes the sample display a short yield platform where the stress remains relatively stable. As a comparison, there is no yield platform where the stress remains relatively stable in the sample with commercial alumina hollow spheres under compression. Due to the formed transition layer, the sample with the self-made ceramic hollow sphere has a significantly higher compressive strength, specific strength and energy absorption performance. Compared with the porous magnesium alloy composite, the compressive behavior of porous composite is subject to that of the metal matrix to a great extent, and the content of Mg in the matrix determines the resultants and the level of the interface reaction. In addition, the compressive strength, specific strength, and energy absorption capacity of the porous aluminum alloy composite are all significantly higher than those of the porous magnesium alloy composite.