STUDY ON INFLUENCE OF PROCESS PARAMETERS TO SUPERPLASTIC FORMING FROM AA7075 ALUMINUM ALLOY SHEET

The paper introduces the experimental research results of superplastic forming of AA7075 aluminum alloy sheet. The experimental planning with 3 elements and 3 levels based on the orthogonal matrix 2 has been formulated, giving a second order regression equation describing the relationship between the relative height of the product and the main technological parameters: forming pressure of 0.7-0.9 MPa, deformation temperature of 500-5300C and forming time of 20-40 minutes. The experimental results are consistent with the general trend of the superplastic forming process: the relative height of the product increases with increasing pressure, temperature, and forming time. However, there exist limit values of forming time, where the law of the influence of temperature and forming pressure on relative height is reversed. Therefore, in each specific machining case, it is necessary to select the range of appropriate process parameters to get the desired results.