Local heat treatment in draw bending for the requirement-oriented production of profile components

The project focuses on advancing incremental bending with integrated heat treatment for the production of adaptable profile components. The objective is to manufacture stress-optimised U-profiles with variable cross-sectional geometry and additional form elements. A wear model aims to improve the prediction accuracy of die lifespan.

Following the results obtained during the first funding period, which demonstrated the feasibility of the draw-bending process with integrated heat treatment for the requirement-oriented production of partially hardened profile components, the second funding period will focus on investigating the process with regard to the production of variable profile geometries. By introducing secondary forming elements, the stiffness of the profiles and thereby their range of applications shall be increased. The additional ability to produce variable profile cross-sections and to apply localised heat treatment enables the manufacturing of components with properties tailored to local loading conditions. To this end, an optimised geometry of the blank outline, as well as the die kinematics, will be developed and analysed with the aid of numerical simulations. Based on this, the draw-bending system will be extended to allow the forming of more complex geometries.

For later industrial implementation, fundamental investigations into the tribological contact conditions and wear behaviour are indispensable. Especially when using secondary forming elements in hot forming processes, increased wear is to be expected. In addition to the technological and scientific challenges, in-depth knowledge regarding die wear during thermally assisted draw-bending must be established. Based on the experimental results obtained in the first funding period, a die wear model for the draw-bending process will be developed. This model will account for the influence of process-specific normal contact stresses, relative velocities, and the temperature-dependent hardness of the die material, and will be implemented into a finite element (FE) system. The simulated wear prediction will finally be validated and used to estimate the die service life.