Study On Bending Process And Springback Control Of Automotive Complex Aluminum Profiles

Light-weighting is one of the important developing directions in automobile industry, and the reduction weight of vehicle body plays a key role in the light-weighting consideration. Taking into account of the requirements in terms of aerodynamics, structural mechanics and aesthetics, automotive extrusion profiles are generally need to bend into a certain curvature. So it proposes a higher demand on surface quality and accuracy of the curved profile. Normally, automotive extrusion profiles with thin-walled, multi-tendon and complex structure. The traditional processing is not only hard to extrusion, but also difficult to follow-up bend forming, severely restricting the application of aluminum alloy materials in the car.In this paper, the finite element model of rotary draw bending for aluminum profiles was established based on the Hypermesh and LS-DYNA software package. The springback and wall thickness variation of aluminum profiles rotary draw bending in different materials state and artificial aging and electrophoresis after rotary draw bending were investigated. The total springback angle is the least when the extruded profiles was processed by cold roll Forming first, then artificial aging or electrophoretic paint. The longer the artificial aging time, the outer wall thinning rate gradually reduced, but the inner wall thickness rate gradually increased.In this study, a new type of extrusion-bending-quenching integrative forming technology was developed. The extrusion profile can be directly bended under warm and hot deformation condition at exit of the extrusion press, this process can avoid drawbacks, such as spring back, cracking and cross-section deformation under traditional cold-formed process, it also can shorten the manufacturing process.The effects of temperature, driving wheel diameter, bending radius etc. on the bend ability have been studied using simulation. Comparing with conventional bending process, the products have high dimensional accuracy and smooth surface, reducing the rebound, cracking and other defects and the strength of profiles meets the product requirements. It indicates that this new forming technology is a ideal method of processing for bending profiles of the aluminum alloys.