The Research Of Tube Electromagnetic Forming Behavior On Two-stage Coils

High-performance tubes have been widely used in many fields for a long time and are an indispensable part of national life and industrial production.Usually the original tube material need to go through the secondary processing,the traditional quasi-static processing technology generally use soft mold expansion method and there are some deficiencies such as low precision,large rebound,poor surface quality and so on.Electromagnetic forming technology is one of the most promising technologies to solve these problems with its high speed and non-contact characteristics.At present,the tube electromagnetic forming technology generally use a single coil,its forming ability,service life and force field control are restricted.In this paper,a method of tube electromagnetic forming based on two-stage coil is proposed.The method can enhance the forming ability through the reasonable cooperation of two coils in time and space.Firstly,the basic principle of the tube electromagnetic forming method based on the two-stage coil is discussed in detail,and the characteristics and realization conditions of this method are explained exhaustively.On this basis,a time-controllable tube electromagnetic forming experimental system on two-stage coil has been set up,the determination of relevant performance of T5 state 6063 aluminum alloy tube which is used in this experiment has also been accomplished.Secondly,this paper analyzes the circuit,electromagnetic field and structure field model of the electromagnetic forming processing,and uses the finite element software COMSOL Multiphysics to realize the simulation of the multi-physical field direct coupling of the tube electromechanical forming on two-stage coils.At the same time,this paper studies the tube electromagnetic forming process on the two-stage coils thoroughly by simulation,and compares the physical quantity in the electromagnetic forming process with the single-coil method,and demonstrates the effectiveness of the two-stage coils method.Finally,the experimental study of the tube electromagnetic forming on the two-stage coils has been carried out.The influence of the discharge voltage of the forming drive coil and the background magnetic field coil,along with the the timing of two coils are studied emphatically.It is found that the two-stage coils method can effectively improve the forming electromagnetic force and increase the deformation of the tube.Furthermore,the increase in the radial deformation of the tube and the expansion of the axial forming area can be controlled by the background magnetic field strength provided by the background magnetic field coil and the two coil discharge timing interval.