Tensile properties of AA6156-T4 friction stir welded joints in as-welded and post-weld aged condition

The effect of the T62 post-weld heat treatment on the tensile strength of AA6156-T4 friction stir welded joints is studied. To this aim, the 0.2% proof stress and the tensile strength of as-welded and post-weld treated joints as function of the rotating and welding speed was analyzed performing a complete factorial design with three levels for each studied parameter. Statistical analyses were carried out to establish empirical models of the tensile prop-erties of the joints as a function of the studied welding parameters. The obtained models were validated through statistical tools such as Mallow's CP, S, & R2 and R2 (adj). The developed regression models can be effectively used to predict the mechanical proprieties of the joints at 95% confidence level.