The main objective aim of this study is to improve mechanical properties of a 7075 aluminum alloy. The alloy composition of a 7075 alloy was slightly modified. To enhance the precipitate hardening effect the content of zinc was increased by 2wt% also, 1wt% cobalt and 1wt% nickel were added to provide the dispersion hardening effect. These alloys were prepared by rapid soidification and hot extrusion. The experimental results suggest that newly developed P/M aluminum alloys exhibit much higher tensile strength than an I/M 7075 alloy. Especially, the alloys produced from fine powders show higher tensile strength and elongation compared to those from coarse powders. Improvements in tensile strength are attributed to suppression or elimination of coarse secondary phases, refinement of grain size and homogeneous distribution of fine precipitate particles, Co₂Al_9, Al₃Ni and oxide particles.