Effect of welding parameters on mechanical and microstructural properties of AA6082 joints produced by friction stir welding

The effect of processing parameters on mechanical and microstructural properties of AA6082 joints produced by friction stir welding was analysed in the present study. Different welded specimens were produced by employing a fixed rotating speeds of 1600 rpm and by varying welding speeds from 40 to 460 mm/min. The joints mechanical properties were evaluated by means of tensile tests at room temperature. In addition, fatigue tests were performed by using a resonant electro-mechanical testing machine under constant amplitude control up to 250Hz sinusoidal loading. The fatigue tests were conducted in axial control mode with R sigma(min)/sigma(max) = 0.1, for all the welding and rotating speeds used in the present study. The microstructural evolution of the material was analysed according to the welding parameters by optical observations of the jointed cross-sections and SEM observations of the fractured surfaces were done to characterize the weld performances. (c) 2007 Elsevier B.V. All rights reserved.