CO2 laser butt-welding of steel sandwich sheet composites

Steel sandwich sheets compared with conventional steel exhibit significant performance improvements such as lower density, higher specific flexural stiffness, and better sound and vibration damping characteristics. However, the main challenge for the broad industrial use is that the joining and assembling methods be used in such a way so as not to alter significantly these characteristics. In the present paper, a laser welding of steel sandwich is examined. The feasibility study of the laser butt-welding of sandwich steel sheets with a CO2 laser beam has revealed that such an approach is possible. A theoretical model of the laser welding process is developed for the investigation of the laser beam impact on both the core and the outer steel layers of the sandwich material. The model presented is based on a novel idea for the simulation of the heat source through the finite element analysis for the estimation of the temperature distribution. Additionally, the effect on the quality of the weld, the strength of the welded sheet, and its damping characteristics are also experimentally investigated and prove that laser welding can be considered as an alternative joining process.