Laser Impact Welding

Abstract

Laser impact welding is a solid-state, collision-based welding process. In this process, laser-generated optical energy is converted to kinetic energy through the ablation at the surface and confinement of the gas generated between a flyer and backing plate. The launch of the flyer can be affected by many factors, for example, backing material, ablative layer, and flyer thickness. In this paper, the effect of three backing materials: glass, polycarbonate and cellophane tape, were studied with different laser spot size and commercially pure aluminum alloy 1100 was used as the flyer. The results show that glass can provide the most efficient launches, but is damaged. Polycarbonate is a good compromise between efficiency and robustness. Welding is possible between many similar and dissimilar material pairs. In this study, commercially pure nickel was joined to commercially pure nickel. There are several possible geometric arrangements of the target relative to the flyer. With flat targets, metallurgical bonding takes place along the edges of the spot, and jet was observed in the center of the spot. Corrugated targets provide more surface area for metallurgical bonding. In this paper, the flyer launch velocity-time profile is also demonstrated using a photon Doppler velocimetry technique.