Rigid/Flexible Medium Combination Superplastic Forming of Industrial 5083 Aluminum Alloy Front Windshield Panel with Large-size and Complex-shape
摘要
This research examined the limited superplastictiy and the rigid/flexible medium combination superplastic forming(SPF) process of industrial 5083 aluminum alloy sheets intended for high-speed train applications with large-size and complex-shape. High-temperature uniaxial tensile tests were performed on this coarse-grained alloy over a range of temperatures and strain rates. The results revealed superplastic-like behavior, with a maximum elongation of 262.5% achieved at 480 °C and 10–3 s−1. Hemispherical bulging tests under varied argon pressures were conducted, and the thickness distribution of different hemispherical regions was measured. Subsequently, a constitutive model was established based on true stress–strain data, and the thermal compensation coefficient between the dies and the AA5083 alloy was calculated and applied to the dimensional design of the dies. The finite element method (FEM) was utilized to predict the thickness distribution during the rigid/flexible medium combination SPF process. Finally, the target front windshield panel was successfully produced by the rigid/flexible medium combination SPF process at 480 °C. Thickness measurements indicated that the maximum thinning ratio was 13.5%, and the maximum contour accuracy error was less than 2.0 mm, demonstrating high geometrical accuracy. Comparative analysis of the initial material and the post-formed material showed a slight reduction in tensile properties, such as tensile strength, yield strength, and elongation, as well as an increase in grain size after the rigid/flexible medium combination SPF process.