EVALUATION OF FATIGUE LIFE OF FRICTION STIR WELDED ۷۰۷۵-T۶۵۱ ALUMINUM ALLOY JOINTS

Abstract – Aluminium ۷۰۷۵- T۶۵۱ alloys are widely used in the production of light weight structures requiring a high strength to weight ratio and high corrosion resistance. The effect of processing parameters on fatigue life of ۷۰۷۵- T۶۵۱ aluminium joints produced by friction stir welding was investigated in the present study. Welding samples were made by employing rotating tool speed of ۷۷۰, ۹۰۰ and ۱۲۰۰ r.p.m, welding speeds of ۷۰, ۷۵ and ۸۰ mm/min. After welding process, mechanical properties of samples were evaluated by means of fatigue testing machine at room temperature. Results were clearly illustrated that as tool speed increases, fatigue life decreases. The highest fatigue life was obtained with ۸۰mm /min welding feed and weld speed of ۱۲۰۰ r.p.m