Investigation on deformation characteristic of electromagnetic punching process in AA5182 aluminum alloy sheet

Electromagnetic punching (EMP) is a dynamic, high-energy and high-speed hole-processing method. In this paper, the EMP specimens under different discharge energies (11–19 kJ) was prepared. By numerical and experimental methods, the deformation characteristic was analyzed, and hole-quality assessments (including morphology observation, dimensional measurements and microhardness test) were implemented. Results showed that the deformation process of sheet consisted of electromagnetic induction, elastic deformation, plastic deformation and separation stage, and the duration of the entire process was within 100 μs. For 11–15 kJ, the sheet had not completed the entire EMP process (no separation stage), and the deformation degree was aggravated with the increase of discharge energy. For 16 kJ, the incomplete punching occurred owing to the insufficient of electromagnetic force and uneven force. As discharge energy continued to increased, the dimensional accuracy of punching improved, the proportion of rollover zone ( η ) decreased, the slant angle of fracture zone ( β ) increased (gradually perpendicular to the sheet plane), the surface morphology of hole wall was more regular, and the micro hardness value of cross section increased, indicating that the punching quality of punched hole was improved. In addition, this work can provide a scientific guidance for the engineering application of EMP technology in automobile industry.