Research On Friction Stir Welding Progress Of5083Aluminum Alloy

5083-H111aluminum alloy using in high-speed train was welded successfully by friction stir welding. Convention mechanics performance of Friction stir welding joints which were welded in different welding speed and rotate speed were studied. The microstructure of typical joint was observed. The results show that, at suitable welding parameter,5083aluminum alloy friction stir welding joint s were forming good, it had the high strength and plasticity at the same time. Joints’tensile strength can reach more than95%of the parent metal and the fracture mode is a typical ductile fracture. The front and root curvature of these joints can reach180degree without cracking. The typical joint’s microstructure is comprised of weld nugget, shoulder affected zone, ATMAZ, RTMAZ and HAZ.. The mechanical property and microstructure in different zones are differing widely because there are different stress condition and thermal cycle in every zone. The hardness distribution of joint look like an inverted V type and the highest hardness appears on weld nugget because of the fine grain. The result of impact test shows that AKv in the middle of joint is obviously greater than AKv in base metal and HAZ.The defects of5083aluminum alloy FSW joint are reached by means of X-ray inspection, observation of microstructure and fracture surface, mechanics performance testing. Both of welding speed and rotate speed influence the heat input of welding and then influence the plastic flow of metal. Weld defects are found in joints which are welded in improper parameter.High frequency fatigue testing shows that the fatigue strength of non-defective5083aluminum alloy FSW joint is135MPa. Fatigue cracks are initiated at the sample surface and extend to inner. For every specimen, the location of fatigue break is base metal. Periodic immersing testing shows that the non-defective5083aluminum alloy FSW joint don’t have a tendency toward stress-corrosion cracking in3.5%NaCl solution.