Deformation behaviour of metal micro tube during hydroforming process

The microtube hydroforming process is a new type of micro forming technology developed based on the traditional tube hydroforming technology. The micro hollow components with complex shapes can be manufactured with metal micro tubes using micro tube hydroforming process. Although some researches have reported the relative research results such as the design of the experimental equipment etc., the microparts produced with the micro tube hydroforming process has the problems of the non-uniform of wall thickness, low bulge height as well as the high failure rate of the forming process. In the current study, FEM simulation of the micro cross shape tube hydroforming process of the micro SUS304 stainless steel tube with a commercial code was carried out. The availability of the FEM simulation model was verified by comparing the maximum bulge heights obtained in the test and simulation. The influence of the deformation parameters of the micro tube hydroforming process on the deformation behavior of the micro SUS304 stainless steel tube were studied by FEM simulation. The internal pressure loading path, the axial feed loading path and the friction coefficients of 0.05 were conducted. The results show that the more uniform thickness distribution and the bigger bulge height of the cross shape part were obtained with the optimized internal pressure loading path and the axial feed loading path. (C) 2020 The Authors. Published by Elsevier B.V.