A single-step hot stamping-forging process for aluminum alloy shell parts with nonuniform thickness

In this study, a single-step hot stamping-forging process using a counter punch was proposed to produce pan-shaped shell parts with nonuniform thickness distributions, which are often used in satellites. Through FE simulations, the effects of die temperature, counter punch initial interposition length and counter force on the part thickness were examined. It was found that the material flow is divided at a flow dividing surface (FDS) which moves in the wall during forming. The maximum bottom thickness and nonuniformity were found to be closely related to the counter force and initial interposition length. Base on the simulation results, experiments were carried out using sheet blanks with initial thicknesses of 4 mm. After stamping-forging deformation, the part bottom was successfully thickened to 4.3 mm while the wall was thinned to 2.5-2.7 mm.