INFLUENCE OF PUNCH SHAPES ON FORCES AND PART QUALITY IN THE PUNCHING OF EXPLOSIVELY WELDED DP600, Al1100, AND DP600-AI1100 COMPOSITE PLATES

This study theoretically and experimentally investigates blanking/piercing operations of explosively welded commercial DP600 advanced steel sheets, Al1100 aluminium sheets, and DP600-Al1100 composite plates, in which punches with different tip shapes are used. The experimental studies included several methods, such as explosive welding, punching, tensile testing, and macro image analyses using digital, optical, and SEM microscopes. The theoretical studies comprised finite element modelling using 3D models. The explosive weld was successfully applied, and the obtained Fe-Al weld microstructure was evaluated. A total of five punches, which have different tip shapes - flat-ended (0°), angled (16°), concave (R1 and R2), and V-shaped (V16) tips - were used in the experiments. Blanking forces were obtained using a load cell mounted to the die, a data acquisition card, an amplifier, and computer software. The simulation and the experimental study results were in agreement and clearly showed the effects of the punch shear angle and shape on the forces required for blanking/piercing.