Invert-Forming of Thin-Walled Tubes Using a Die

The production of sound thin-walled tubular parts by invert-forming is generally limited to components having geometrical features within a compact range. Recent published works in the field present new results relevant to process and die design. However, gaps of knowledge can still be found in understanding the influence of design parameters and interface friction on the overall formability of the process. The aim of this paper is to extend the actual knowledge of the process by means of a comprehensive theoretical and experimental investigation. The theoretical investigation is supported by numerical predictions based on the finite element flow formulation and the overall methodology is assessed by means of experimental tests on AA6060 aluminium-alloy tubes under laboratory-controlled conditions.