Analysis of deformation behavior in various incremental tube forming processes

ABSTRACT

Incremental Tube Forming (ITF) is a comparatively new forming process in which the ends of a tube are expanded into the desired shape using a hemispherical tool. ITF process finds its applications in various sectors like automotive, aerospace, and heavy industries for interconnection of the piping system, structural elements, etc. It is crucial to analyze the tube’s deformation behavior for its successful forming and good accuracy of the formed part. The current work investigates the tube’s deformation behavior during the grooving and tube end forming in single and multistage strategies. Both the experimental and simulations are performed to analyze the strain distribution, thickness variation, and formability of the AA6063 tube. The experimental and simulated strain distribution reveals that the bottom end of the tube where forming started is in the plane strain state and the free end of the tube is uni-axial tension. The thickness variation and reduction percentages for experimental and simulations are in agreement with each other. An error of less than 2% was found for thickness variation at all the considered wall angles. Finally, the microstructural analysis performed using electron back scattered diffraction (EBSD) technique has revealed the changes in grain size, local misorientations and grain aspect ratio formed at various wall angles.

KEYWORDS:

• Incremental
• tube
• forming
• deformation
• grooving
• springback
• formability
• forces
• thickness
• strain
• distribution
• microstructure

Additional information

Funding

This work was supported by the BITS RIG grant [BITS/GAU/RIG/2017/73.].