Saeed Sanayei - M.sc, Iran University of Industries & Mines
Morteza Tamizifar - Associate Professor, Department of Materials Engineering, Iran Science and Industry University
maryam ahmadiyan - B.sc,Padide Mavad, Science and Research Institute

Friction stir welding can be used vastly for joining aluminum alloys such as 7075 aluminum alloys that are hard to weld by conventional fusion welding .Heat affected zones are susceptible of corrosion in chloride media ,which is not an acceptable problem. One of methods is to enhance corrosion resistance of heat affected zone after welding by heat treatment, but it has been reported that fine grains are not stable during solution treatment in stir zone. In this study, effect of axial force is examined before and after post weld heat treatment with 5 mm thickness in aluminum alloy. The results show that the intermetallic particles are broken up during friction stir welding zone, and severity of the breaking up of intermetallic particles and grain size in the stir zone increase with intensifying axial force. Consequently stability of grains and corrosion resistance increase in chloride solutionduring heat treating in joint area

7075 Aluminum alloy. Friction stir welding .Polarization Tofel, T6Heat Treatment