Single Point Incremental Forming (SPIF) is a forming process in which a fully clamped sheet is formed by a hemispherical ended tool that moves along a predefined 3D toolpath. The sheet is formed in a series of local deformations to reach its desired shape. Double Sided Incremental Forming (DSIF) includes one tool on each side of the sheet so that the second tool can take the role of the local die or the forming tool to improve the part shape geometry and forming parts with higher geometric complexity. Significant advantages of incremental forming process include, (i) low tooling cost due to easy fabrication and geometry independence of the tools, (ii) absence of the heating energy cost due to room temperature nature of the process, and (iii) its capability of forming complex parts which make it suitable for low volume forming of the polymer sheets as well as prototype fabrication. This work investigates the effects of SPIF process parameters on formability and failure mode in polymer, metal-polymer laminates, mechanical and microstructural properties, and chain orientation of the formed polymers. Capability of DSIF process in forming polymers is also shown and discussed.
Investigation on the effect of SPIF process parameters on formability and mode of failure shows that increasing incremental depth increases formability; however, this advantage is limited to the occurrence of wrinkling. The results show that the mode of failure depends on incremental depth and shape of the part being formed. Additionally, tool rotation speed reduces forming forces. Investigation of the influence of SPIF on mechanical properties and chain orientation of the formed polymers shows that SPIF increases the strain at fracture and Ultimate Tensile Strength (UTS). Yield stress and Young’s modulus in the formed polymers are reduced as compared to the unformed polymers. The effect of process parameters on formability and failure mode in SPIF of Metal-Polymer laminates is also examined and it is shown that polymer thickness has a significant effect on formability. Additionally, the feasibility of forming polymers with DSIF process is presented. Preliminary results show that DSIF increases the formability and geometric definition as compared to SPIF.