Multi-directional incremental sheet forming-a novel methodology for flexibly producing thin-walled parts

How to perform sheet metal forming in a rapid and cost-efficient way, especially for the small-batch productions, has been a challenge to the manufacturing industry for a long time. Incremental sheet forming (ISF) has vast potentials in rapid and economical production of small-batch thin-walled parts, but so far, the technology is mainly applied in a limited forming range of planar sheets, most with a deformation mode of bi-axial stretching. To establish a more complete forming chain based on ISF and then take full advantage of it, this paper proposed a new methodology called Multi-directional Incremental Sheet Forming (MISF), particularly aiming to accomplish the non bi-axial stretching formation of thin-walled structures such as flanging, curling, and localized forming of planar sheets and hollow profiles. The method can not only extend the application of conventional ISF, but also can fabricate some special-shaped shell components which are hard to integrally form by any other ways. Thus, it can provide a strong support to realize the lightweight of structures. The progress review of MISF was presented, and the mechanical features during forming, including the complex coupled elastic-plastic deformation, buckling and post-buckling, the combination of constrained and free deformations, etc., were summarized. Moreover, key items of defect control were addressed.