Abstract: TIAD (Tube inversion by the axial drawing) is an advanced forming process for manufacturing double-walled tubes with high quality, high efficiency, low consumption. However, whether to realize forming process depends on whether to produce the tearing in deforming zone, which has a close relationship with deforming force. Therefore, it is important to study the influence of forming condition parameters on the deforming force by FEM numerical simulation for the realization and the development of TIAD precision forming process. The results obtained show：(1) During the whole forming process, the shape of the tube keeps unchanged, so the precision forming can be easily realized; (2) For a given r/d0 or d0/d0, the deforming force depends mainly on the value of r/d0, and there is a critical parameter k, when r/d0k, the steady forming force increases with the increase of r/d0; (3) The material hardening exponent n of the tube has a remarkable influence on the deforming force. The smaller the value of n, the larger the forming force. The influence of friction coefficient on the deforming force is relatively small, however, good frictional condition will help to improve the surface quality of the part gained.

Key words: Precision forming, Deforming force, FEM, Tube Inversion by the axial drawing