Dieless Double-Sided Incremental Hole-Flanging With Different Toolpath Strategies

Incremental sheet forming is a flexible manufacturing process that does not require dedicated dies nor custom tooling. Hole-flanging via the ISF process is rapid and cost-effective, especially in prototyping and low-volume production. In this study, a double-sided incremental hole-flanging method was considered where the top and bottom tools were used as the forming tool and supporting tool respectively. Utilization of these generic, stylus tools provides enhanced flexibility and replaces the need for specific blank holders. The double-sided incremental hole-flanging method was experimentally studied with various toolpath techniques for the forming and supporting tools. Two toolpath strategies were determined that developed a successful symmetric hole-flange. The measured wall thickness was found to be comparatively uniform along the wall of the flange, while in-plane strains demonstrate excellent material formability. Additionally, the optimum strategy was trialed on a self-designed complex profile with shrink flange and stretch flange occur alternatively in an effort to demonstrate the flexibility and generality of the proposed double-sided incremental hole-flanging method. Possible future work in this area is also discussed.