Elucidating the deformation modes in incremental sheet forming process: Insights from crystallographic texture, microstructure and mechanical properties

This study investigates the exact state of deformation in single point incremental forming (SPIF) and double-sided incremental forming (DSIF) techniques using experimental observations of texture evolution coupled with a multiscale simulation of the processes. The texture evolution was investigated for different sets of forming parameters such as vertical displacement, wall angle and tool diameter. It was observed that difference in crystallographic texture due to change in tool diameter and vertical displacement was marginal. However, significant difference in texture evolution was observed upon changing the wall angle. Further analysis of crystallographic texture revealed that role of through thickness shear (TTS) is limited in case of DSIF process compared to SPIF process. Numerical simulation of SPIF process via finite element method was successful in capturing the contribution from TTS in SPIF process. Based on insights obtained from finite element calculations, Visco-Plastic Self-Consistent simulations were carried out which were successful in predicting the experimental texture. Finally, the effect of different incremental forming techniques on the mechanical properties of the formed components was studied. The observed anisotropy in yield strength was explained based on the inverse of average Schmid factor. Lankford parameter and yield locus were also estimated from the experimental textures to understand the feasibility of incremental forming at different wall angles.