An investigation into the production of a large-scale automotive part included small features using hydraulic sequential forming method

Abstract

Aiming at the requirement of the formability and the surface quality of the large-scale aluminum alloy such as AA6016-T4, utilized in the automotive component with complicated structures, a sequential forming process is proposed. This method consists of sheet hydroforming technology and local shaping with rigid tools. Firstly, according to the hydroforming process, the small curvature surfaces with excellent surface quality and the partial deformation of the local small features are obtained. After that, the method of local shaping with rigid tools is adopted and causes to reduce the equipment tonnage. In this research, the sequential forming process is studied on the basis of numerical simulations and experiments. At the same time, substituting the conventional mechanical test, the influences of different loading modes on the mechanical properties of the material are studied further from the viewpoint of the microstructure analysis. So when the different forming process is finished, the material in different areas is sampled and the microstructure evolution law is observed. The research results are illustrated that the excellent agreement is found through the analysis and the comparison of the wall thickness values on different measuring sections in the experiments and simulations results and the part with excellent quality is obtained. Meanwhile, it is found that the change degree of the microstructure of the small local features in the local shaping is more intense than the hydroforming process, and the grain sizes in the local shaping are smaller than the hydroforming process, and it is illustrated that the sequential forming is essential to the production of the aluminum alloy part with excellent surface quality and accurate structure size.