On the laser beam absorption efficiency in laser welding of aluminium thin sheet with copper pipe

Abstract

Abstract Welding is considered the most versatile joining method, with extensive applicability in every modern industrial field. Especially, laser welding technology is widely utilized due to its numerous advantages, and its capability to process a variety of different materials. Among the several process parameters that impact the welding results, the absorbed energy and the power density are of major importance. These parameters mainly depend on the utilized materials and their physical properties, as well as the laser beam inherent characteristics. Moreover, the welding of more complex shapes and geometries is even more challenging, since multiple scatterings are taking place as well. The current paper presents a simulation model of the laser beam path and its absorption in the case of welding an aluminium thin plate and a copper pipe. The Ray Tracing method has been employed, while, the model’s geometrical parameters, are dimensionless, reduced to the pipe's radius. The materials’ absorption coefficient is calculated as a function of the incident angle, while the multiple scatterings are taken into consideration. From the simulation, the total absorption, as well as the relevant power density are calculated for a series of different initial process control parameters, i.e., spot size, incident angle, relevant laser spot position.