Aluminium alloy AA7075 (Al–Zn–Mg–Cu) is one of the precipitate hardened aluminium alloys used in aircraft industrie due to its high strength to weight ratio, together with low density. Despite of its good properties, this alloy exhibits weakwearehavior when it undergo wear application. Therefore, large number of attempts has taking place to increase its friction resistance. In present study, surface nano composite of Al/Al 2 Cu and Al/Al2Cu-Al2O3 was produced via friction stir processing on the surface of aluminum alloy 7075. Therefore, this alloy was processed 1, 3 and 5 passes using speed of 1000 rpm and 20 mm/min. result showed that friction stir processing of base metal resulted fine and equaxed grains. But hardness and wear resistance of base metal was decreased due to dissolution and reprecipitation of MgZn 2 particles. 1, 3 and 5 passes were conducted to produce surface nano composite with Cu and CuO strengthening particles. XRD and EDS were used to determine the phases. Also, microstructural observation were conducted via optical and scanning electron microscopy (SEM). Results showed that the Al 2 Cu intermetallics Al 2 O 3 phase have been produced due to in situ reaction of matrix and strengthening particles and samples which were made by 5 passes showed increase of hardness and wear resistance in comparison with base metal. However, as result of dissolution and growth of precipitates, there is no significant change of hardness and wear resistance of composited samples. Consequently, composited samples had undergone T6 treatment in order to produce precipitates. Hardness and dry sliding wear test Observations revealed that T6 treatment improved the composited samples surface properties. Furthermore, to evaluate high temperature surface properties, pin and disk wear test were done in 300 0 C. considering the superior thermal stability of intermetalics in comparison with MgZn 2 precipitates, all samples showed improvement in wear behavior compared to base metal. 5 passes samples illustrated the best wear resistance behavior due to their more intermetallic content. Keywords Aluminum Alloy 7075, Friction Stir Processing, Intermetalics, Wear behavior, Hardness.
