Enhancement of Laser Impact Welding for Joining Thicker Aluminium Sheet

Abstract

This study critically examines the efficacy of Augmented Laser Impact Welding (ALIW) in achieving high-quality welds by leveraging the effects of laser-induced plasma and controlled impact forces. Therefore, various Gunpowder Nitromethane (GPN) compositions were examined. The results demonstrated that the incorporation of 0.1 g of micro-air bubbles into a mixture of 1 g smokeless powder and 10 g of 95% nitromethane significantly enhances the flyer velocity. Moreover, the usage of Sapphire instead of borosilicate glass as a confinement layer can be a great alternative due to its damage resistance after each laser shot. Furthermore, the refined GPN composition was employed in experiments with a 1 mm Al 6061-T6 flyer, where different spot sizes and varying GPN thicknesses were tested to determine the optimal conditions for this specific flyer thickness. The findings revealed that the maximum flyer velocity was achieved when using 0.54 mm of GPN-3 in conjunction with a 5.22 mm laser spot size.