Analisys of FSW welds made of aluminium alloy AW6082-T6

Purpose of this paper is to analyze the results of tests on the mechanical properties and microstructural changes in Friction Stir Welds in the aluminium alloy 6082-T6 in function of varying process parameters. Design/methodology/approach: the produced tensile strength of the produced welds was measured and the correlation with process parameter was assessed. The welds’ microstructure in various zones was analyzed using an optical microscope. Microhardness measurements were performed on the welds’ cross-sections. Findings a tendency was observed of the mechanical resistance of test welds to increased with the increase of travel (welding) speed, maintaining constant rotational speed. Hardness decrease was observed in weld nugget and heat affected zone, of entity inferior that that of fusion welds. Origins of tunnel (worm hole) defects were found and analyzed. Research limitations/implications: various combinations of process parameters were used to produce the test welds, but without the possibility of controlling the downward force. Further extension of applicable parameters combinations should be examined. Practical implications: the increase of mechanical resistance with increasing welding speed offers an immediate economic return, as the process efficiency is increased. Originality/value: information contained herein can be useful to further investigate on the possibility of improving the properties of FSW welds, as well as the efficiency of the process.