The effect of welding speed on the microstructure and mechanical properties of dissimilar aluminum alloys joined by friction stir welding

In this study, dissimilar Aluminum Alloys (AA) 2014 and 5083 have been friction stir welded by using a constant rotation speed of 1600 rpm and three different welding speeds. The aim is to determine the optimum welding speed for such a dissimilar joint. Temperature measurements, microstructural examination, hardness measurements and room temperature tensile tests have been carried out in order to determine the optimum combination. For all welding speeds, a fine-equiaxed grain structure is obtained in the nugget zone with similar grain diameters. The tensile testing results show that the mechanical strength of the dissimilar joints, in terms of tensile strengths, was found to be 60% for AA 2014 and even for AA 5083 base metal values for 106mm/min welding speed, highest among the three welding speeds