A new dieless forming method for metal bellows induced by local thermal buckling

A new dieless forming method is proposed to produce metal bellows induced by local thermal buckling. The thermal buckling forming process is realized according to the local deformation behavior of metal tubes under the action of high temperature softening and axial pressure. In this paper, a forming device is designed and it is capable to produce metal bellows in two forming modes of a discontinuous bellow forming process and a continuous bellow forming process. FEM simulations are used to analyze this thermal buckling forming process and its product performance. The results show that the presented process can increase wall thickness and improve the energy absorption performance of metal bellows. Meanwhile, some thermal buckling forming cases of metal bellows of different materials and different sizes are presented.