Plastic deformation behavior of bi-metal tubes during magnetic pulse cladding: FE analysis and experiments

Magnetic pulse cladding (MPC) technology, which is based on sequentially impact welding portions of long tubes, offers the distinct advantage of utilizing only a small amount of energy stored on the capacitor to fabricate bi-metal tubes. It remains necessary, however, to develop a method for successfully controlling and enhancing cladding quality during MPC. This paper provides insight into the plastic deformation behavior of bi-metal tubes subjected to progressive magnetic pulse force, using experiments with the FE method. The effect of the field shaper on the plastic deformation was also investigated to facilitate the field shaper design, where the parameters considered are the geometrical characteristics, known as the inclined angle α1 and α2 on the work zone of a field shaper. Results show that a bamboo-like shape produced on the outer surface of the clad tube was a result of inharmonious plastic deformation behavior. The modification of a field shaper by setting an inclined angle α2 works more effectively than shortening the feeding length in terms of improving bamboo-like shape, due to change in the magnetic field during the second step of the MPC process. Additionally, two kinds of typical plastic deformation responses corresponding to local and progressive collision patterns were identified during MPC. It was found that the inclined angle α2 and actively setting of inclined angle α1 at 3° on the work zone proved critical factors in determining plastic deformation response in the MPC process. These results demonstrate that the proposed numerical approach successfully elucidates fundamental details on critical behaviors during the MPC process, and can be used to assist process design.