Multi-step hydroforming process and wall thickness optimization of 5A02 aluminum alloy five-way tube with different branch diameters

Abstract

The different branch diameter of ve-way tube affects the design of loading internal pressure in the hydroforming process, where the large-diameter branch is broken more easily than the small-diameter one due to the same ultimate stress of tube material in one-step forming method. Therefore, the rst four-way and then ve-way of multi-step forming (FFTF) method and the rst three-way and then ve-way of multistep forming (FTTF) method were proposed to fabricate the 5A02 aluminum alloy ve-way tube with two kinds of branch diameters to avoid the burst of large-diameter branch tube. The nite element simulation of ve-way tube hydroforming process shows that the height of small-diameter branch tube is lower and serious wrinkles appear at the large-diameter branch tube in the one-step forming and FFTF method. By optimizing the length of punch, a ve-way tube with a big branch height and uniform wall thickness was obtained with the FTTF method. The approach of lengthening the punch in the experiment increased the height of formed branch and reduced the wall thickness reduction rate of ve-way tube in FTTF method.Overall, the ndings mentioned above can not only offer guide in creating ve-way tube with excellent quality, but also be taken as reference to the hydroforming studies on multi-way tube in the future.