Robot-Assisted Cold and Warm Incremental Sheet Forming of Aluminum Alloy 6061: A Comparative Study

Incremental sheet forming (ISF) requires no or partial dies for sheet metal fabrication and is widely used for small batch production. In this process, necking is either suppressed or delayed due to the localized nature of tool-sheet contact; hence, more strains than conventional stamping and deep drawing are obtained. In the present study, two variations of ISF, namely cold ISF (CISF) and warm ISF (WISF), are compared. First, FEA modeling is carried out on ABAQUS to reach the forming forces involved in the process. It is found that WISF reduces the forming forces. The temperature for WISF is maintained at 180 degrees C. Following the simulation analysis, tests are carried out. The forming force in WISF is 55.77% less than that in CISF. The part fabricated by CISF is slightly more substantial than that by WISF; however, more forming depth can be achieved by WISF. There is a more uniform thickness distribution in the case of CISF than in WISF. However, the surface quality of the CISF product is inferior to that of WISF. It is observed that there is reduced forming force, increased formability, and better strain distribution in WISF compared to CISF. However, post-processing heat treatment and surface polishing of the formed parts is required to restore their mechanical properties.

Automated summary

Incremental sheet forming (ISF) is widely used for small batch production in sheet metal fabrication, and it does not require or only requires partial dies. This study compares two variations of ISF, namely cold ISF (CISF) and warm ISF (WISF). FEA modeling and tests show that WISF reduces forming forces, but CISF produces more substantial parts while WISF achieves greater forming depth. CISF has a more uniform thickness distribution, but WISF has better surface quality. WISF also has reduced forming force, increased formability, and better strain distribution compared to CISF.