Effect of Stretching on Springback in Rotary Stretch Bending of Aluminium Alloy Profiles

Abstract

Stretch bending is widely used for manufacturing profile-type parts. However, one of the challenges faced by the bending-type forming processes is springback, which significantly reduces the dimensional accuracy of formed part, process flexibility and overall equipment effectiveness. In this study, we focus on the springback behavior in a newly developed flexible rotary stretch bending process for profiles. Using the Al-Mg-Si alloy rectangular hollow extrusions, the effect of stretching on springback, as well as process capability, is evaluated by a series of carefully designed experiments conducted for a wide range of stretching strains. Increasing the stretching strain from about 2% to 4%, the springback chord height can be reduced by about 32% and the process capability can be improved significantly, showing the strong ability of the novel flexible stretch bending strategy for controlling springback and dimensional accuracy.