Mechanical characterization by DOE analysis of AA6156-T4 friction stir welded joints in as-welded and post-weld aged condition

Abstract Tensile properties of AA6156-T4 friction stir welded joints were studied in the as-welded and T62 post-weld heat treated condition. To analyze the influence of rotating and welding speed on the 0.2 % proof stress and tensile strength of the two classes of joints, a complete full factorial design with three levels for each studied parameter was performed. Statistical analyses were carried out to establish empirical models of the tensile properties of the joints as a function of the studied welding parameters. The obtained models were validated by statistical tools such as Mallow's C P , S, R 2 and R 2 (adj). The developed regression models can be effectively used to predict the mechanical properties of the joints at 95 % confidence level.