Local Thickening of Thin-Walled Tubes by Boss Forming

This paper explores the application of incremental sheet-bulk forming by means of a tube boss forming process that is capable to reduce and locally pile-up material in thin-walled tubes. Local thickening of the tube wall thickness allows creating three-dimensional functional features for subsequent forming and assembly operations. The presentation is focused on the development of a flexible laboratory tool system capable of performing boss forming of thin-walled tubes in unit cells made from various materials and geometries. Special emphasis is placed on the design of the tool system taking into consideration the process formability limits. Information on the mechanical and formability characterization of the tube material gives support to the work.