Design of laser-textured surfaces to enhance the strength of adhesively bonded joints

This paper tries to relate the laser treatment process parameters to the morphological properties of laser-treated aluminum alloy surfaces and the adhesive joint fracture load in butt joint configuration to describe their pivotal role as surface roughness design parameters. In these contexts, the role of the individual process parameter and energy density on the surface and joint characteristics were experimentally investigated. Surface roughness was modeled and validated to demonstrate that it is designable and controllable. Moreover, to globally understand the effect of the laser parameters on joint fracture load, experimental results were analyzed following a DoE framework. This study shows that laser-treatment parameters contribute significantly to surface roughness control. Model-based surface morphology and the consequent average surface roughness can be accurately predicted, i.e., groove characteristics of the surface can be accurately controlled by regulating the laser-treatment parameters. Optimal laser parameters allow designing a surface that maximizes the adhesive joint fracture load.