Experimental and Numerical Analyses of Magnetic Pulse Forming of A1050 Aluminum Sheet

抄録

An A1050 aluminum sheet was collided against a steel mold with a small V-shaped through-thickness groove by using magnetic pulse forming (MPF) at various charging energy conditions. Deformation behavior of the sheet was also reproduced by using a series of numerical analyses. The groove was filled at high charging energy condition. Almost no change in grain morphology was observed at the mid-thickness area of the sheet, but extremely large intensive deformation occurred at the metal surface region along the slope of the mold. Deformation of the MPFed Al sheet was numerically analyzed by using ANSYS Emag-Mechanical. Electromagnetic force and deformation of the sheet was reproduced, and the impact velocity of the sheet to the mold was obtained. Deformation behavior of Al under various impact velocity conditions was analyzed by using Smoothed Particle Hydrodynamics (SPH) method of ANSYS AUTODYN. The groove was completely filled with Al at the high impact velocity condition, and an extremely large plastic strain and strain rate were observed only at the sheet surface. These simulation results corresponded very well to the final shape and the local microstructure change observed in the MPFed Al sheet.

Fig. 9 Deformation behavior of the Al sheet reproduced by Model 2 by using SPH method. For 2 kJ condition, (a) the moment of collision, (b) 0.5 µs from collision, (c) 1.0 µs and (d) 1.4 µs. For 6 kJ condition, (e) the moment of the collision, (f) 0.4 µs from collision, (g) 0.8 µs and (h) 1.1 µs. (i) and (j) Enlarged views of the area indicated by black arrows in (f) and (g).