The significance of friction in the single point incremental forming process

The Single Point Incremental Forming Process (SPIF) makes use of a single, small forming tool to incrementally deform a metal sheet into a complex shape. Without a need for dedicated tooling, this process meets the demand for small batch production and Rapid Prototyping of industrial shell-like structures. The sheet is formed due to a locally applied stress field on its surface, consisting of a normal and a shear component. The shear component is strongly influenced by friction with the dragging forming tool. In common practice, SPIF is performed under well lubricated conditions and with tool rotation, both designed to minimize friction. Through-Thickness Shear (TTS), which is part of the deformation mechanism in SPIF, may be intuitively linked to the friction applied during the process.