Integrated manufacturing of AA6082 by friction stir welding and incremental forming: Strain analysis of deformed samples

Flexible manufacturing systems have attracted increasing interest especially to produce highly customized components or for manufacturing of prototypes/small batches. Among others, the single point incremental forming (SPIF) process has been successfully applied in several non-structural applications, e.g. architectural lining, decorative element manufacturing and rapid prototyping. Nevertheless, accuracy, toolpath definition and reduced productivity are still relevant issues, in particular when tailored banks are processed. The present work discusses an integrated manufacturing route combining welding and forming of aluminum sheets. More specifically, attention has been focused on the strain distribution induced by the single point incremental forming of friction stir welded AA6082 sheets. The used method consists in the generation of digital 3D twins of the undeformed and deformed shapes by means of ScanProbe and Matlab software packages. The displacement field, evaluated from the comparison between initial and final positions of surface points, is then used as input in a FE model that estimates the final strain distribution. Forming limit diagrams (FLD) have been evaluated for welded sheets and compared to the forming limit curve of conventional forming processes. Obtained results have been finally compared with strain distributions detected in fusion welded sheets.