GAS PRESSURE FORMING OF 2024 ALUMINUM ALLOY IN A HEMISPHERICAL DIE
This paper is focused on forming hemispheres from the commercial 2024-T3 aluminum alloy at different temperatures, pressures and the walls thickness variation for the formed hemispheres. The aluminum alloy do not exhibit superplastic properties under conventional processing conditions and for this it was thermo-mechanical processedfor grains refining, in order to improve deformation characteristics. The gas pressure forming tests were carried out at the temperatures of 460°C, 480°C and constant pressures of 0.75 MPa, 0.8 MPa, using aluminum alloy sheets of a 0.67 mm thickness, obtained from thermo-mechanical processing. The polar heights of the sheets have been measured as a function of the forming time. The results of tests showed that for formed hemispheres the walls thickness gradually decreases with increasing of height from base to pole and the largest thinning of the walls is obtained at the pole of these.
Key words: 2024 aluminum alloy, thermo-mechanical processing, grains refining, gas bulge forming test, thickness distribution.
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