Benchmarking and Refining the Vaporizing Foil Actuator Spot Welding Process

Abstract

Impact spot welding implemented by the vaporizing foil actuator welding method has been studied. With significantly lower input energy levels as compared to resistance spot welding, similar and dissimilar lap welding of aluminium alloys (AA) of types 5052 and 7075 was implemented. The dissimilar welds between 2 mm thick AA5052 and 2.3 mm thick AA7075 were created with 4 kilojoules input energy, whereas the similar welds between 1 mm thick AA5052 sheets required only 0.6 kilojoules. Flyer sheet velocities of approximately 750 m/s were measured with a PDV system. Microhardness measurements, performed across the dissimilar weld interfaces, showed no softening of the base materials due to the welding process. A few distinct welding configurations were investigated for improving process feasibility and obtaining the highest possible weld strength. Lap shear tests and pry tests revealed that the configuration of the starting weld geometry greatly affected weld quality.