Investigating the effect of heat treatment in hydraulic rotary draw bending of AA6063 tubes

Thin-walled tube bending is one of the important processes for manufacturing parts in the automotive and aerospace industries. This paper investigates the effect of heat treatment on the bendability of thin-walled tubes made of AA6063 alloy. With the hydro rotary draw bending process, the cross-section ovality of the as-received, annealed, and artificial aged tubes has been examined at different fluid pressures. In the experiments, the tube diameter to tube thickness ratio was 13.88. Also, the critical bending ratio was 1.6, and the bending angle was 90 degrees. By examining the results, it has been found that heat treatment and fluid pressure had an important effect on the quality of the bent tubes. By increasing the fluid pressure to 3.6 MPa, critical cross-section ovality has decreased in all specimens. The maximum decrease of cross-section ovality is obtained in the annealed sample by 49%. Also, in the artificially aged specimens, the critical cross-section ovality decreases by about 45%. It has also been observed that at a pressure of 3.6 MPa, the critical cross-section ovality of the annealed sample has improved by 19% compared to the artificially aged specimens.