Improvement of Product Properties by Selective Induction of Residual Stresses in Incremental Sheet Metal Forming

Funding: German Research Foundation (DFG)
Project: 372803376 (SPP 2013)
Contact: Fabian Maaß M. Sc.

The aim of the second funding period of the priority program is to improve metal component properties through forming-induced residual stresses.

In collaboration with the department of Metallic Materials of TU Berlin University the Single Point Incremental Forming (SPIF) process is analyzed with regard to the targeted adjustment of residual stresses. The potential of influencing the residual stresses in a specific way through the forming process was proven in the previous funding period. Based on a numerical process model (see Figure a), a SPIF process enhancement using a flexible polyurethane die is established (see Figure b). This process enhancement even enables an introduction of compressive residual stresses at the tool side of the component (see Figure c). Eventually, the fatigue strength of cyclic loaded components is to be increased through the targeted SPIF-introduction of residual stresses. The research also considers the influence of disturbance values on the residual stress generation.

a) Numerical process model, b) Process set-up, c) XRD measurement results