Nanostructured composites of aluminum 7075 alloy (Al-7075) of carbon coated silver nanoparticles (Ag-C NPs) were synthetized by powder metallurgy in a high energy ball mill at different milling times in order to determinate the effect in the mechanical properties when nanometric size ductile particles are added into the aluminum matrix alloy, the characterization of the powders were carried out by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, microhardness and by sieve shakers. It was found that silver nanoparticles have a positive effect in the refining the particle powder size as well as in the crystallite size of the composite. The MgZn2 phase, responsible of the age hardening in the alloy is dissolved or fragmented during the mechanical milling process, the Ag-C NPs presence promotes the nucleation of the MgZn2 phase. The mechanical properties of microhardness increase as the milling time increases, as well as with the nanoparticles content increment. (C) 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.