关键词: 管材胀形, 滑动摩擦, 力学模型

Abstract: A mechanical model considering sliding friction between the tube and die is proposed to explore the plastic deformation behavior of the tubes during a expansion process in a square cross-sectional die. That the radius of the circular arc with the minimum limit value is firstly proved, and the calculational formulas are given, based on researching on the no friction slipping model. The minimum radius of the circular arc which is defined can decide the workpiece’s shape and forming pressure. At last, experiments of tube expansion in a square die using a self-designed apparatus are also conducted. The ex-perimentation results are between no friction slipping model and friction slipping model. The correctness of no friction slip-ping model and friction slipping model is also verified by con-trast with experiments and calculation results.

Key words: Mechanical model, Slipping friction, Tube expansion