Powder aluminum composites of Al–Cu system with micro-additions of oxide nanoparticles

Abstract

Aluminum composites doped with copper (4 wt %) with micro-additions (0.01–0.15 vol %) of oxide nanoparticles (Al₂O₃, ZrO₂, MgO, SiO₂) are synthesized by the powder metallurgy method. Their microstructure and mechanical properties (Brinell hardness number, Vickers microhardness) are investigated. Existence of phases CuAl₂ both on the boundaries and inside grains of the matrix are revealed. Optimal concentrations of nanoparticles that provide high mechanical properties are determined. For Al–Cu material with 0.15 vol % of aluminum oxide, a maximum increase in Brinell hardness of 17% (68 HB) with respect to aluminum composite without nano-additions sintered according to the same technology is observed. Among the investigated materials, the highest Vickers microhardness of 0.543 GPA is intrinsic to aluminum composite with Al₂O₃ content of 0.1 vol %.