Locally heat-assisted torsion forming of metal tubes for improvement of mechanical properties based on microstructure control

A locally heat-assisted torsion forming process for metal tubes is proposed and integrated in the conventional dieless drawing process. The part of the tube heated by a laser is subjected to torsion deformation due to the difference in the rotation speed of chucks. Pure aluminum tubes A1050 are used in the experiments, and excessive torsional deformation causes unstable deformation. The microstructure is controlled by the amount of torsion. The strength, ductility, and Lankford value are enhanced by the microstructure control in the proposed process. The process can be applied to the continuous mass manufacturing of metal tubes with high performance.